Do some homework before visiting Hong Kong's antique stores

Almost anything Chinese - whether Tang Dynasty tricolor jars, Ming molded gourds, or cheap jade trinkets - can be bought in Hong Kong. For the average buyer, ''decorative'' seems to be the key word, although you should take note of the many unobtrusive shops with their mere dozen or so Sung Dynasty or Tang pieces lined up on a shelf. These are serious dealers for serious collectors with esoteric tastes and interest in only the very top pieces.

In the Hong Kong antique stores looks can be very deceiving. The buyer must know what he wants. If he doesn't, he may not see a collection a shop may have.

Gammon Art Gallery, for instance, keeps little more than a handful of objects on display. The proprietor, King Kong Lee, says, ''If someone comes in and says, 'Is this all you have?' we say, 'Yes, it is.' If a customer looks around and doesn't know what's on display, then he doesn't have the right to sit down and chat.''

If it sounds intimidating, it's probably meant to. This doesn't mean, however , that you need your inheritance in hand to make inquiries or even purchases.

Adopting the point of view of art museums - with educational purposes in mind and limited budgets - you can acquire a collection of beautiful objects. Set some rules, do your homework, and proceed forthrightly.

Says Laurence C.S. Tam, curator of the Hong Kong Museum of Art, ''If you are willing to put up with small flaws, you can acquire a beautiful collection at a surprisingly low price. In this museum, we satisfy ourselves with building up a study collection with quality as the standard - not personal taste, exquisiteness, or extreme rarity. We recently acquired a Blue & White plate with a hairline crack across three-fourths of the plate. It's scarcely visible, but flaws like this can often reduce the price of a piece by one-half.''

Mr. Tam has straightforward advice for would-be collectors: ''Build up your background on a particular subject by reading in two directions - the history of the people making the art objects and then the history of the art form itself. That's not sufficient in itself, of course, for you must look at actual objects.''

Internationally, there are numerous first-class museum collections of Chinese art. Anyone's list of the best in the United States would include the Museum of Fine Arts in Boston, New York's Metropolitan Museum of Art, the Freer Gallery of Art in Washington, the Art Institute of Chicago, the Cleveland Museum of Art, the Nelson Gallery of Art in Kansas City, and the Asian Art Museum of San Francisco.

These are some of Hong Kong's best dealers:

* P. C. Lu & Sons Ltd., Mandarin Hotel, Hong Kong, plus Peninsula Hotel, Kowloon.

* Charlotte Horstmann & Gerald Godfrey Ltd., Ocean Terminal, Kowloon.

* Robert Chang, Ocean Terminal, Kowloon.

* T. Y. King & Sons, Swire House, Hong Kong.

* Gammon Art Gallery Ltd., Bank of America Tower, Hong Kong.

* S. H. Chan, Mandarin Hotel, Hong Kong.

* Eileen Kershaw, The Landmark, Hong Kong, and the Peninsula Hotel, Kowloon.

For information and assistance call the Hong Kong Tourist Association, 35th Floor, Connaught Center, Hong Kong; telephone (5) 244-191.