William Joseph Black, 43, an associate professor of architecture at the University of the District of Columbia, died of cancer Saturday at his home in Silver Spring.

Mr. Black came to the Washington area in 1974 from New York, where he had practiced architecture and urban planning for New York State. He was an expert on the architecture and social dynamics of Harlem and had written numerous articles about that neighborhood and its history.

He was the author of Visions of Harlem, Past, Present and Future," which is scheduled to be published next year. Mr. Black was a photographer as well as an architect and he took many of the photographs that will appear in the book. The pictures now are part of the collection of the Museum of Modern Art in New York.

Mr. Black was born in Texas and grew up in Chicago. He attended the University of Illinois and earned bachelor's and master's degrees at Columbia University in New York. He received several grants for travel and study in Europe, Africa and Latin America.

He was director of the Harlem office of the New York City Planning Commission, a project development coordinator for the New York model cities program, executive director of the Harlem Jazz Music Center, and a program development consultant for the New York States Urban Development Corp.

Since moving to the Washington area, he had continued to work on his book on Harlem in addition to carrying on his teaching duties. He also had pursued his interests in jazz and photography.

Survivors include his wife, Romaine H. Black, of the home in Silver Spring; his mother, Gracie Black, of Chicago; his father, Willie Black, of Long Beach, Calif,; a sister, Dorothy Love, of Chicago, and three brothers, John, Doug, and James, all of Chicago.