George W. Carter Jr., 38, a copy editor for the Weekly sections of The Washington Post, was found dead Sunday at his Arlington home.

James Beyer, deputy medical examiner for Northern Virginia, said after an autopsy yesterday that a determination of the cause of death is "pending." Dr. Beyer said a toxicology examination and analyses of tissues and blood have been scheduled.

Mr. Carter was found in bed by a friend. He has last been seen alive Thursday night, but did not come to work Friday or keep an appointment Saturday night. Officials said he had been dead between one and three days when he was discovered.

A native of Abilene, Tex., Mr. Carter had been a newspaperman for 14 years, almost all that time as a copy editor - editing stories and writing headlines. He began at The Post as a copy editor on the metropolitan staff in November, 1970, and had transferred to the Weekly at its inception in June, 1975.

The oldest of five children of a farmer, Mr. Carter grew up in Abilene, in Tucumcari, N.M., and in Booneville, Ark., where he attended high school.

He graduated from Arkansas Polytechnic College in 1963 with a BA degree in English and journalism. While at the Russellville, Ark, school, he edited both the yearbook and the student newspaper.

In September, 1963, he joined the Arkansas Gazette in Little Rock as a copy editor. He left the following February to become news editor of the Pine Bluff (Ark.) Commercial, but he returned to the Gazette, again as a copy editor, in October, 1964. Mr. Carter remained at the Gazette until he joined The Post.

An Army veteran and a member of the reserves, Mr. Carter served a total of one year on active duty - six months in 1956 and another six in 1962.

A quiet man who had strawberry blond hair, he was an avid outdoorsman, and often returned to Arkansas on vacations to hike, camp, canoe and swim. In the Washington area, Mr. Carter often spent weekends the same way, and was a canoeing veteran of the Potomac and Shenandoah Rivers.

Mr. Carter is survived by his parents, George W. Carter Sr. and Ora Mae Carter, of Booneville; three brothers, Frank, of Olathe, Kan., Leslie, of Port Arthur, Tex. and Joseph, of Booneville; a sister, Mary Ann-Bridges, of Greenwood, Ark., and by his former wife, Margaret, of Washington.