Reginald C. Price, 66, a civil engineer, economist and Quaker activist, died of cancer Saturday at his home in Bethesda.

Mr. Price, who held engineering degrees from the University of Wisconsin, worked for state, federal and international agencies, starting with the Wisconsin State Board of Health, and including the Departments of Agriculture and Interior, the Federal Power Commission, the United Nations and the World Bank.

In the 1960s, he was deputy director of policy for the California department of water resources. He also served in the far East for more than 10 years. His last resident assignment there was as water resources adviser to the United Nations Mekong Committee.

He returned to his area in 1972, and was an adviser and consultant to several organizations, including the Environmental Protection Agency.

He was a longtime member of the Friends Meeting of Washington and active in Quaker activities to promote peace and social justice.

Survivors include his wife, Esther; a son, Lee N., of Belmont, Calif.; two daughters, Margaret Prag, of Williams, Ore., and Laurie, a graduate student at the University of North Carolina, and two grandsons.

The family suggests that expressions of sympathy may be in the form of contributions to the American Friends Service Committee, 1501 Cherry St., Philadelphia, 19102.