Charles M. Schwartz, 49, a civilian employee of the Army Corps of Engineers and a active Air Force Reserve officer, died of cancer Yuesday at his home in Alexandria.

Born in Brooklyn, N.Y., he served as an enlisted man in the Army Air Corps from 1945 to 1946. He then earned a bachelor's degree from the University of Connecticut and was commissioned in the Air Force Reserve in 1950.

After receiving a master's degree in forestry from Duke University Mr. Schwatz joined the Army Corps of Engineers. From 1951 to 1966 he was an intelligence research specialist and a land-use geographer.

Since 1966 he has specialized in tropical veketation, land use and forestry.

He also played an active role in Air Force Reserve intelligence, working with American prisoners of war. he was instrumental in obtaining a tax extemption for POWs and served as a debriefting officer during project "Homecoming" when prisoners were returned from Vietnam. He recently received the Legion of Merit for that service.

He is survived by his wife, Ruth Schwatz of Silver Spring: three children, Michael, of Takoma Park, and Gary and Nancy, both of Silver Spring: his parents, Mr. and Mrs. David G. Schwatz of Hollywood, Fla., and a sister, Suzanne Liberman, of Portland, Ore.

The family suggests that expressions of sympathy may be in the form of contributions to the American Cancer Society or the National Foundation for Cancer Research.