A writer who captures the Russian character;

Sandro of Chegem by Fazil Iskander Translated from the Russian by Susan Brownsberger New York Ardis/Vintage Books 358 pp $9.95 Paperback. Fazil Iskander is one of the Soviet Union's most original and popular authors. Although he has lived in Moscow for two decades, he is highly regional. His home is the ancient land of Abkhazia in the Soviet Republic of Georgia.

No doubt world interest in his writing has been largely muted by the obscurity of Abkhazia and its people, the subject of his fiction. But that has been our loss. For not since Turgenev's ''A Sportman's Sketches'' has the Russian character been presented with such humor and beauty.

It would be all too easy to compare Mr. Iskander to Mark Twain, Swift, Gogol, and even Chaucer; he is very much in the tradition of irreverent, biting satire. But the writers who most readily bear comparison to him are Gabriel Garcia Marquez and Sherwood Anderson. In the chapter ''Gamblers'' there is a kind of magical lyricism that is both regional and universal:

The cattle dealer, because he was winning, played noisily, spoke familiarly to fate; he called his dice with laughter, with humorous catch phrases, which unnerved the Greek and gave the Endursky an added psychological advantage.

''Shash-besh-hey!'' he said. ''Bear

'em away!''

''Du-bara-dubrinsky,'' he reported,

''dances the lezginky!''