LOMA LINDA, Calif. (AP) _ A 10-day-old California girl remained in critical but stable condition today, two days after receiving a heart transplant, hospital officials said.

The condition of the infant, identified only as Baby Victoria, was unchanged since she underwent the five-hour operation Saturday morning at Loma Linda University Medical Center, nursing supervisor Molly Lura said today.

''All is going quite well,'' hospital spokeswoman Anita Rockwell said Sunday.

The transplant was performed by Leonard Bailey, who gained worldwide attention with the controversial transplant of a baboon heart into a girl known as Baby Fae in October 1984.

Baby Victoria suffered from hypoplastic left-heart syndrome, a fatal condition in which the left side of the heart is seriously underdeveloped, Ms. Rockwell said.

The child is the eighth infant under 6 months to undergo heart transplant surgery at the hospital since November 1985.

Five of the seven previous young patients are ''all doing fine,'' Ms. Rockwell said.

In keeping with hospital policy, Ms. Rockwell withheld the identities of the latest patient and her parents. And no information was released about the baby heart donor.