Ursula l. walz, 56, a program analyst and information specialist for the laboratory of pathophysiology at the National Cancer Institute since 1972, died of cancer Tuesday at the home of her sister, Doris E. Titus, in Bethesda.

Born in Arlington, Mas., Miss Walz graduated from Simmons College in Boston. Before coming to the Washington area in 1952, she was a medical technician at the University of Michigan Hospital and a laboratory instructor at the University of Michigan School of Public Health.

In the 1950's, she worked as a microbiologist at the Walter Reed Army Institute of Research and was head laboratory technician in the Department of Microbiology at the University of Maryland Medical School

She returned to Simmons in 1957 to earn a master's degree in library science and for the next four years was a reference librarian at the Harvard Medican School.

Miss Walz, who returned to this area in 1961, lived in Kensington. She was a reference analyst at the National Institute of Mental Health, a microbiologist at the National Cancer Institute and a medical librarian at the National Institutes of Health. She returned to the National Cancer Institute in 1972.

She was member of the American Association for the Advancement of Science, the Medical Library Association and the Special Libraries Association.

Besides her sister, survivors include two brothers, Hans G. Walz of Wellesley, Mass., and Thomas C. Walz of Newagen, Maine.

The family suggests that expressions of sympathy be in the form of contributions to Home Care at Holy Cross Hospital in Silver Spring, to the Montgomery Hospice Society Inc. in Bethesda, or to the Montgomery County Humane Society.