David Dodge, acting president of the prestigious American University of Beirut founded by his missionary grandfather in 1866, was abducted at gunpoint from the campus today, according to eyewitnesses.

Two men first tried to force the 60-year-old American into a red Renault stationwagon, then beat him on the back of the head with a pistol butt when he resisted and shoved him into the car, according to a student who watched the kidnaping.

The abduction was the first involving an American since the Israeli invasion began June 6. Dodge also was kidnaped during the 1975-76 civil war.

None of the many armed Lebanese factions publicly claimed responsibility for the Dodge kidnaping, but its timing, on the eve of crucial talks in Washington between President Reagan and the Saudi and Syrian foreign ministers, was seen as a bad omen in jittery West Beirut.

Both Palestine Liberation Organization leader Yasser Arafat and Lebanese Prime Minister Shafiq Wazzan made known their concern.

In the violent world of Lebanese politics, all sides regularly have resorted to kidnaping either to bring about the release of their own abducted victims or to advance other claims.

An eyewitness said that one of the kidnapers who abducted Dodge was heard to shout "Amal," the Arabic word for hope which is the name of the Shiite Moslem militia.

One Amal faction is currently allied to Iran's Islamic revolution.

Although long identified with Beirut, Dodge, who is married and the father of four children, technically calls Princeton, N.J., home.

He is a Princeton University graduate and served for many years as an executive with Tapline, the trans-Arabian pipeline company which ran a refinery at the Mediterranean port of Sidon.

In 1978 Dodge became AUB vice-president for administration before serving in his present capacity. The new president, Malcolm Kerr, was formally due to take over July 1, but his arrival has been delayed by the war.