August Sebastiani, 66, head of one of California's largest and most highly respected wineries for 30 years, died of cancer Saturday in his home in Sonoma Calif.

The Sebastiani holdings are among the last remaining great family vineyards and wineries left in California. The family began in the wine business when Mr. Sebastiani's father, Samuele, purchased a 501-gallon redwood tank and some Zinfandel grapes in 1904.

August Sebastiani took over the concern in 1944 modernized and expanded the winery, and made it famous for its Italian-style red wines, especially the Barbera a variety some authorities say may have gotten its start in California at Sebastiani.

Until recent years, Mr. Sebastiani could be seen in coveralls working the land and moving barrels. He disdained offers to buy his holdings. "I would as soon sell my children as my vineyard," he once told a wine critic.

He also was known as conservationist, with more than a thousand birds in his aviary, and many rare and endaggered species wandering the grounds and vineyard irrigation reservoirs. Thousands of migrating waterfowl were provided with food and resting places by Mr. Sebastiani.

It was on the Sebastiani lands that several Grayson doves, thought to be extinct, were discovered. Mr. Sebastiani had been active in recent years in bringing the doves back.

Mr. Sebastiaini's first love was his wine. He was proud of the ribbons he won in California shows. As he once told a group of congressmen. "Wine is just as much a food as mustard or catsup or anything else you add to food make it taste better. Having wine with your dinner makes everything taste better."

When he was told he had terminal cancer more than a year ago, Mr. Sebastiani placed the operation of the business in the hands of a son, Sam.

In addition to his son, Mr. Sebastiani is survived by his wife, Sylvia; another son, Don; a daughter, Mary Ann Cuneo: a sister, sabinia McTagger, and 10 grandchildren.