Robert J. Mondloch, 47, an official of the Department of Agriculture in Washington, died Monday in New Orleans following a heart attack.

Mr. Mondloch began his career with Agriculture in 1955 in his hometown of Little Falls Minn. At the time of his death, he was director of the conservation and environmental protection division of the Agricultural Stabilization and Conservation Service.

Earlier he had served as assistant to the director and director of the envirronmental quality and land use division of USDA. Mr. Mondloch transferred to Washington from Minnesota in 1967.

Before beginning his government career, he attended Crosier College in Onamia, Minn., and Marquette University in Milwaukee. Mr. Mondloch served in the Army during the Korean war.

Survivors include his wife, Joyce M., of the home in Alexandria; two daughters. Beverly A. Whitmore, of Langley Park, and Lou Ann, of the home; six sons. Thomas R., of Hillsville, Va., Daniel R., of Charlottsville, Va., Richard J., of Harrisonburg, Va., Kevin J., Roger J. and Gregory J., all of the home, his parents, Mr. and Mrs. Joseph Mondloch, of Little Falls, Minn., and five sisters.

The family suggests that expressions of sympathy be in the form of contributions to Bishop Ireton High School in Alexandria.