Two men armed with an unidentified weapon robbed a female undergraduate late Monday night near the entrance of Lowell House, Saul I. Chafin, chief of University police, said yesterday.

The victim, who was uninjured, told police that the two men approached her on Holyoke Place, the street that ends at the Lowell House archway, at about 10.50 p.m., Chafing said. He added that one man grabbed her from behind and the other pointed an object at her stomach and said. "Drop your purse."

Chafin said the victim could not identify the object the man was holding, but "she assumed it was a gun."

After taking the purse which contained $145--the men field, but the victim could not tell officers in which direction, Chafin said.

He added that she did give a description of the man who grabbed her a Black male, about 5-ft. 11-in tall, wearing a brown jacket and a knit cap. Detectives are working to locate the man.

"It was a quick hit." Chafin said, adding. "We would encourage students not to carry that large a sum of money at that time of night."

According to the most recent University police statistics, released for the week ending January 23, the incident is the 23rd robbery reported on Harvard property since July 1.