Howard Hines, convicted of murdering a Japanese student studying at the University of Maryland, yesterday pleaded for his life before the Prince George's County jury that will decide whether he should be sentenced to die in Maryland's gas chamber.

In a rambling and confused 10-minute speech that included poetic passages from the Koran, Hines told the jury: "I don't want to die, and I love my life like anyone of you love your life." Hines made little reference to the 1979 stabbing death of 22-year-old Michiyo Nakada for which the same jury convicted him last month.

The 29-year-old Alabama man did offer an explanation for hitting a child in the head with a brick when he was 8 years old. Hines said that he was defending his sister who had just had her "long, pretty hair," cut off by schoolmates.

Earlier in Hines' sentencing hearing, in an effort to show that Hines was dangerous, Assistant State's Attorney David Simpson told the jury about that childhood incident and about Hines's extensive criminal record, including one conviction for rape and another for child molestation.

Hines' attorneys, Joseph M. Niland and Eugene M. Yannon, had advised him not to address the Circuit Court jury. But After Hines made his rambling speech, Yannon said that he was not sorry: "I think that he reinforced some of the things we were trying to say . . . . His sense of reality isn't our sense of reality."

During closing arguments yesterday, Niland told the jury that "this murder was committed while Mr. Hines was substantially impaired" by a mental disorder. Last week a psychologist hired by the defense described Hines as a paranoid schizophrenic who would have been out of control when the murder was committed. Niland also asked the jury to consider that Hines was only 25 when the murder was committed, and the attorney also said that his client was the victim of an "unfortunate" childhood that was lacking in parental supervision because his mother died when he was young.

Prosecutor Simpson told the jury he did not believe the argument presented by the psychologist and said that Hines acted deliberately when Nakada was stabbed 40 times on a pathway near her Hyattsville apartment.

In accordance with a new law that requires a victim-impact statement at sentencing hearings, Simpson read exerpts from a letter prepared by Nakada's family, currently in Japan.

The woman's parents said they had sold family property to send their daughter to America to study, but that she "could not do so in safety and peace." The Nakadas said the shock of their daughter's death, which they learned of through a television news report as they sat eating supper, was overwhelming. To this day, Simpson said, Mr. Nakada has been emotionally unable to observe a Japanese custom of leaving daily offerings at a household shrine for his dead daughter.

The jury is scheduled to begin its deliberations today.