Eleven children of Vietnamese-American parentage arrived in the United States today, the largest such group to leave Vietnam in seven years and the first of an expected influx of Amerasian children.

Included in the group of seven girls and four boys was 12-year-old Kenneth Linh Brooks, a girl whose mother is nervously awaiting the child's scheduled arrival in Washington, D.C., Monday afternoon.

Gary Tanous, 42, of Camas, Wash., who went to Vietnam last week and left there Thursday with the group, said, "I'm exhausted at this point, but I'm very happy," as he stood beside his 15-year-old daughter Jean Marie after their arrival from Tokyo.

Bright-eyed Huynh Tranh Tung, 11, on his way to Willcox, Ariz., shyly declined to speak in front of the bright television lights. But an escort said, "He wasn't shy at all on the plane. He was running up and down."

Smiling and seemingly alert despite the 9 1/2-hour overnight flight from Tokyo, the children who arrived here aboard Pan American World Airways Flight 002 passed through customs and dispersed to connecting flights or to the homes of friends in the area.

"I'm happy, and I'm sad," said Nguyen Quoc Viet, 11, speaking through an interpreter. "I'm happy that I'm going to see my father in Sacramento, but I'm sad to have left my friends and relatives behind."

Officials estimate that at least 3,800 Amerasian children in Vietnam have proof of their American parentage that will allow them to follow this group to the United States and escape what for many has been a life of particular hardship because of the political and ethnic taint of their connection to the United States.

The arrival of the children, ages 7 to 15, and several of their relatives came two days after the Congress passed a bill granting U.S. citizenship to them and thousands of other Amerasian children who can prove American parentage.

Vietnamese call them bui doi (dust children) because many must make their living in the streets, sometimes resorting to crime and prostitution in a setting where they are sometimes denied housing, ration cards and schooling.

The number of children in Vietnam, Thailand, Japan, South Korea and other Asian countries fathered by Americans has been estimated at 80,000 to as many as 250,000.

Richard Walden, an official of the relief agency Operation California, said 3,800 children in Vietnam had proven U.S. parentage and would begin taking the Thursday flights from Ho Chi Minh City to Bangkok as the first leg of their trip to the United States.

The lives of children arriving here have been full of family complications but none more complicated involved than those facing the three children of San Diego security guard Luis Villegas.

His three children, Marco, 13; Linh Da, 11, and Dora, 10, their mother Nguyen Thi Chinh, 47, and her two daughters, 24 and 22, from a previous marriage, all arrived on the Pan Am flight, the largest single family group.

Villegas, who awaited them tonight in San Diego where they headed after a connecting flight, had registered each child at its birth during his eight years working as a construction mechanic in Vietnam but the sudden collapse of the U.S.-backed South Vietnamese government prevented their exit.