Alonzo S. Rice, 47, a vice president and director of Colonial Dodge in Rockville, died at his home in Rockville Saturday following a heart attack.

Mr. Rice was born in Jackson, Ohio, and grew up there and in Springfield, Ohio. In 1951, he enlisted in the Air Force and served in Korea during the conflict there.

He then was transferred to Washington and stationed at the old Atomic Energy Commission. He remained at the AEC after his discharge from the Air Force in 1955. His duties involved the design and production of brochures, exhibits and other visual graphics. He attended the Corcoran School of Art.

In the early 1960s, Mr. Rice formed his own advertising company, Rice Associates. The firm did layouts and design for the suburban Maryland Builders Magazine and other work. Mr. Rice also worked for the William Gelberg Sign Co. and was a consultant to the AEC. He later designed traveling exhibits for Discom Inc. In 1968, he formed Schoolhouse Visuals, a firm that designed educational games.

He began his career with Colonial Dodge in 1971 and rose from salesman to vice president in charge of personnel, advertising and community relations.

Survivors include his wife, Judith, and three children. Paula, Christine and Eric, all of Rockville.

The family suggests that expressions of sympathy be in the form of contributions to the Heart Fund.