Matthew Maxwell Taylor Kennedy, 13, a son of the late Sen. Robert F. Kennedy, was rendered unconscious yesterday in an elevator accident at the Rockville home of his uncle, R. Sargent Shriver Jr.

The youth was listed in stable condition and under observation last night in the intensive-care unit of Suburban Hospital in Bethesda, where he was brought about 3:30 p.m.

A spokesman for the hospital said that the youth had apparently suffered a head injury but that X-rays showed no fracture. A family spokesman said the youth was in no danger.

His mother Ethel Kennedy was at his bedside, the hospital spokesman said, and his aunt Eunice Shriver was also at the hospital.

Tom Southwick, press spokesman for the youth's uncle Sen. Edward M. Kennedy (D-Mass.), said that the youth had "passed out," but had recovered consciousness before 6 p.m. yesterday. The aide said details of the accident were not immediately clear.

"They have an elevator in the Shrivers' house (and) Max got caught in it," Southwick said."He was trying to push one of the buttons."

As he understood it, Southwick said, the elevator was going down and the youth was reaching in. "I'm not sure that anybody really knows how it happened," he said.

An ambulance from the Rockville volunteer fire department arrived at the house at 2:45 p.m. After the youth was found to be unconscious, the mobile intensive care unit of the Bethesda-Chevy Chase rescue squad was dispatched. The mobile unit took the youth to the hospital.

Southwick said Mrs. Shriver and one or more of her children were in the house at the time of the accident, the injured youth is the ninth of 11 children of Robert and Ethel Kennedy. He lives at the family home in McLean.