No-compromise Chicago mayor relies on no-nonsense staff chief.

When Chicago Mayor Harold Washington's chief of staff received an envelope containing $500 from a local union last Christmas, he turned it over to a police officer with instructions to take it back and get a receipt.

And William F. Ware, whose fifth-floor City Hall office is only a few feet away from the mayor's, clearly expects no more such ''gifts'' this year.

''The word is out,'' says the mayor's chief administrative aide with a grin. ''Everybody tried to figure out during the first few months of this administration how to get in ... (but) we basically refused to go to dinner.''

Indeed, one of the key positions taken by the Washington administration dates back to early campaign days: Its influence is not for sale and that Chicago's machine brand of wheeler-dealer politics would not continue. Just a few weeks ago the mayor returned campaign contributions to 13 city contractors who exceeded the $1,500 limit he set during his campaign.

Mayor Washington is under fire from an increasing number of local civic leaders who say his zealous pursuit of reform without compromise is damaging the city.

The mayor counters that he will not be blackmailed into ''making a deal'' with the City Council majority, a group at odds with him on almost every major move.

Looking back over the 15 months since Washington took office, Mr. Ware views the changes made so far - in opening up local government and instituting more businesslike management practices - as major contributions to Chicago's political and economic progress.

In an interview in his office, where a large colored photograph of Chicago's nighttime skyline covers one wall, Ware recalls the difficult financial and administrative situation that his boss inherited:

''The biggest bucket of cold water for us coming in was ... seeing that what was being spent versus what we could ever expect to raise had gotten so far out of 'sync,' and realizing the real significance of the federal cuts - that there was just much less there than in the past,'' he says.

Committed then to forcing city government to live within its means, the Washington administration promptly reduced the city's work force (except firemen and police) by 17 percent and just recently reimposed a hiring freeze in all departments.

The 3,000 people let go, Ware says, translate into a $100 million-a-year saving. Also, he says, the administration immediately hired New York's Lazard Freres & Co. (consultants to such once-financially troubled cities as New York, Cleveland, and Detroit) as financial advisers. ''Usually you wait until you're in real trouble and then hire somebody like that to get you out of it,'' Ware says.

Then, too, he adds, the mayor has tried to select technically competent professionals to appointed positions both in departments and on boards rather than to reward friends.

''We've been criticized ... (but) I think there'll be a payoff from that down the road,'' he says.

Also, despite Mayor Washington's vow to pay much more attention to city neighborhoods (which worried some business leaders), Ware insists the administration has made ''consistently pro-development decisions - even in the face of opposition from community

groups.''

In his view, the racial climate in Chicago has also improved since the city elected its first black mayor.

''We have a much better rein on the police force,'' he says. ''There's a feeling that you don't go out and get aggressive with people that look different - because the mayor's office wouldn't stand for it.'' He recalls going early to a blues festival with the mayor and his party. Young people with beer coolers (''hard-core Woodstock types'') had taken over the front seats. ''The police started to really mix it up with the kids until they saw us.... Then they kind of relaxed and let it all happen.''

Ware, a graduate of the University of Chicago Law School with a preference for tailored dark suits and classical music, has worked for both the American Civil Liberties Union and the US Equal Employment Opportunity Commission. He came aboard Harold Washington's team in 1981, when the the mayor was a Congressman. The Mayor, who has said that he knew within minutes of meeting Ware that he was the man to run his office, frequently refers to his aide as a first-rate administrator.

Those less close to Ware sometimes refer to him as the Washington team's ''mystery man,'' for his low-key manner, or as a ''workaholic'' who delegates few details to others.

Ware concedes he prefers some anonymity for added effectiveness. And he does often work a 15-hour day, including Saturdays and a chunk of most Sundays.

''I usually stop in between church and dinner,'' he admits, ''but Saturday nights are mine.''

But he insists his so-called obsession for detail grew out of necessity: ''In the beginning things were all terribly unstructured and uncoordinated and had traditionally been that way. And we brought in people who were new to government and who had a lot of questions and a great need to sort of check in and be reassured....

''A real effort was made to rein things in to be sure that everybody was singing from the same hymnal.... With almost everything that was done you had to jump in the middle of it to make sure that some detail, some safeguard was in place.''

The situation now, he says, has improved.

''Where I used to get phone calls asking, 'Can we think about this?' I now get decision memos, saying, 'This is to inform you,' '' he says.

Also helping is the addition of a new staff assistant: Ernest Barefield, a former aide of Atlanta Mayor Andrew Young.

''I'm very optimistic about how we're doing administratively,'' Ware concludes. ''We've saved a lot of money, and generally I think there's a feeling now that government is much more accessible to people.''