Ann Ervin Royster, 83, a founder of the Democratic Women's Club of Bethesda who was active in civic and volunteer work, died of a coronary occlusion Tuesday at her Bethesda home.

After moving to Bethesda in 1929, Mrs. Royster helped found the Women's Democratic Club there. She also was active in the women's auxiliary at Suburban Hospital in Bethesda and in the Montgomery County Thrift Shop.

Mrs. Royster served as president of the Newcomb Club of Bethesda and was a member of the Women's Board of Montgomery General Hospital for a number of years. She also served on the founding board of what was said to be the first public library in Bethesda.

She was an active member for more than 50 years of St. John's Episcopal Church in Chevy Chase and served as director of the Alter Guild and as a member of the Women of St. John's.

Mrs. Royster was born in New Bern N.C., and grew up in Raleigh, N.C.

In 1916 she married Percy Hoke Royster, a former head technical adviser in the metallurgical division of the Bureau of Mines. Mr. Royster died in 1966.

Survivors include a daughter Patsy R. Lozupone of Bethesda; a sister Kathryn E. Brooks of Alexandria, two grandsons and four great-grandsons.

The family suggests that expressions of symphathy be in the form of constributions to the Heart Association.