Simon Krupsaw, 78, owner of the historic Old Antique House at 817 Pennsylvania Ave. NW in Washington, died of Parkinson's disease Monday at the Washington Home, where he had lived for the last year.

The Old Antique House, an antique store and import establishment, was founded by Mr. Krupsaw's father, Nathan, in 1884. It is said to be the oldest store on the avenue between the Capitol and the White House.

Simon Krupsaw entered the family business at the age of 11. He made more than 100 buying trips to Europe during his career and made headlines on two continents in 1960 when he purchased 10,000 pieces of china and enamel objects and more than 500 pieces of 18th century English furniture in Sussex, England.

Mr. Krupsaw once told The Washington Post that he grew so fond of some of his treasures that he had trouble parting with them.

"I just keep them," he said, "and show them to people." He then picked up a tiny gold box and said, I wouldn't sell this for anything."

One treasurer he never parted with was the Old Antique House. It is still in the family and is run by his son, Stanley.

Mr. Krupsaw was a native of Washington. He was a member of the Amity Club of Washington and had belonged to the Samuel Gompers Masonic Lodge for more than 50 years. He was a member of the Adas Israel Congregation.

In addition to his son, of Potomac, Mr. Krupsaw's survivors include his wife, Mollye Goldman Krupsaw of Washington; a daughter, Marlene K. Berch of Damascus; two sisters, Yetta K. Cohen of Washington, and Cecelia K. Galler of Malvern, Fla., and six grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the Washington Home, 3720 Upton St. NW, or to the Metropolitan Heart Guild of Washington.