Ed Offterdinger of Bethesda, who won the qualifying medal with 69, won his first- and second-round matches yesterday and gained today's quarterfinals of the District Amateur golf tournament at Argyle Country Club.

Offterdinger defeated Ed Volm of Robin Dale, 2 and 1, in the morning and Kim Dickerson, also of Robin Dale, 1 up, in the afternoon.

Offterdinger will face Tom Flory of Prince Georges in this morning's first quarterfinal match, which is scheduled to begin at 8:30.

That match will be followed by Gary Marlowe of Woodmont versus Dave King of Bethesda; Randy Morris of Washingtonian versus Gill FitzHugh of Army Navy, and Gary Moore of Prince Georges versus Gary Fox of Robin Dale.

Marlowe, former Maryland Open and Amateur champion, defeated Terry Burke of Congressional, 1 up, in the morning. He eliminated Glen Barrett of Cedar Crest in the afternoon in 23 holes, winning with a par on the fifth extra hole.

Barry McCarty of Belle Haven, champion two years ago, was eliminated in the first round by Moore, 1 up. Moore then defeated Don Wright of the host club on the 18th hole.

King, last year's runner-up, defeated Mike Adams of Springfield, 3 and 2, and Edward Klein of Bretton Woods, 2 and 1.