Roswell Whitaker, 38, principal of Bell Career Development Center, a vocational center for high school students in the D.C. public school system, died Monday at George Washington University Hospital. He had multiple myeloma.

Mr. Whitaker, who was a native of Whitakers, N.C., graduated from Fayetteville (N.C.) State University, Fayetteville, N.C., and was a teacher in North Carolina before moving to Washington in 1966. He began his career in the public schools here as a mathematics and science teacher at Bell Vocational High.

In 1972, he was named prinicipal of Bell Evening School. Mr. Whitaker became assistant principal at Ballou Senior High in 1973 and was named principal in 1977. He was appointed principal of the Bell Career Development Center in 1979.

Mr. Whitaker received an outstanding teacher award in 1972. He also received an administrator-of-the-year award in 1975.

Survivors include his wife, Evelyn, and two sons, Damon and Cedric, of Largo, Md.; his parents, Mr. and Mrs. Joseph Whitaker of Whitakers, N.C.; two brothers, Joseph Earl of The Bronx, N.Y., and Lorenzo, of Durham, N.C.; two sisters, Lillian Whitaker of Hackensack, N.J. and Gwendolyn Whitaker of Rocky Mount, N.C.; and one grandmother, Dora Speight of Whitakers, N.C.