Marvin Chauncey Ross, 72, a museum curator and authority on Byzantine art, died of cancer Sunday at George Washington University Hospital.

A former curator in Baltimore and Brooklyn, Mr. Ross became curator in 1959 of Hillwood, the treasure-filled Washington estate of the late Marjorie Merriweather Post.

Hillwood housed millions of dollars worth of jewels and art, most of it from Russia and France. Mr. Ross remained in charge of the treasures until Mrs. Posts's death in 1973.

He then became curator of the collections she had given earlier to the Smithsonian Institution and was a consultant there until his death.

He was the author of two catalogues on parts of the Post collections, "The Art of Krl Faberage and His Contemporaries," published in 1965, and "Russian Porcelains," published in 1968.

He also was the author of two volumes of the "Catalogue of the Byzantine Antiquities in the Dumbarton Oaks Collection," published in 1962 and 1965. At his death, he was compiling another major work on Byzantine art.

Born in Moriches, N.Y., Mr. Ross received bachelor's and master's degrees from Harvard University and took further studies in art at New York University, University of Vienna, and in Madrid.

He was an instructor in art at the University of Pittsburgh in 1928 and 1929. He then became curator of medieval art at the Brooklyn Museum.

From 1934 to 1952, Mr. Ross was curator of Byzantine medieval and subsequent decorative arts at the Walters Art Gallery in Baltimore.

He also served as a captain in the Marine Corps in World War II, and from 1944 to 1945 was deputy adviser on monuments, fine arts and archives at SHAFF.

From 1952 to 1955, he was chief curator at Hillwood, he spent a year in County Museum. After becoming curator to Hillwood, he spent a year in 1960 and 1961 as Fulbright lecturer on Byzantine art at the Kunsthistorisches Institute at the University of Vienna. Mr. Ross, who lived in Washington contributed to many art periodicals. He was the editor of "The West of Alfred J. Miller," published in 1951 and revised in 1967, and of "George Gatlin: Last Rambles with the Indians," published in 1959.

He is survived by two sisters, Erma DeWitt, of New Paltz, N.Y., and Zora Kelley, of Suffolk County, Long Island.