Nils Birger Mattsson, 62, director of the computer systems division of the Department of Health and Human Services' Alcohol, Drug Abuse, and Mental Health Administration and a member of local Finnish cultural groups, died of cancer May 10 at his home in Silver Spring.

Mr. Mattsson was born in Helsinki and graduated from the Swedish School of Economics. Before coming to the United States in 1957, he had completed postgraduated work for law and mathematics degrees at the University of Helsinki.

He was a medical researcher at the University of Michigan until 1963, when he moved to this area and joined George Washington University as deputy directory of the biometric laboratory.

He was a senior systems scientist for the IBM Corp. here and worked for the National Institute of Mental Health before being named director of computer systems at the Alcohol, Durge Abuse, and Mental Health Administration in 1971.

Mr. Mattsson was an officer of the national capital chapter of the Finlandia Foundation.With his wife, Eira, and his son, Eric, he performed with Finnish cultural groups, such as the Finnish Folk Music Ensemble's Kalevala Combo and the Finlandia Folk Dancers, at international folk festivals and at the Smithsonian Institution, the Renwick Gallery, the Marvin Center at George Washington University and a Wolf Trap.

He also sang with the Montgomery County Masters Chorus, which will dedicate its May 24 concert of Mozart's Great Mass in C Minor to his memory.

During World War II, Mr. Mattsson was an officer in the Finnish armed forces and was awarded the Finnish Freedom Cross with swords and oak leaf cluster.

Besides his wife and son, both of Silver Spring, survivors include a brother, Sven, of Helsinki.

The family suggests that expressions of sympathy be in the form of contributions to the Finnish Disabled War Veterans Associations, Kasarmikatu 34, 00130 Helsinki 13, Finland, or to the Georgetown University Hospital.