The State Treasurer Melba Till Allen was sentenced to three years in prison yesterday for her May 24 conviction on conflict of interest charges. Under state law, she automatically was ousted from office upon being sentenced to prison. Attorney J. Doyle Fuller, who represents Allen, said, however, she has not decided whether to challenge the applicability of the law to her office.

Allen stood between her two attorneys, displaying no emotion as the sentence was imposed by Hooper. Asked if she had anything to say, Mrs Allen told the court. "So help me God, I am not guilty." Immediately after her sentencing by Circuit Judge Perry O. Hooper, Allen's attorney filed notice of appeal.

Allen was convicted May 24 on two counts of using her office to obtain a loan and line of credit from the American Bank at Geneva, Ala. She faced a maximum $10,000 fine and 10 years in prison Allen is scheduled to go to trial on June 19 to face two more charges - that she used her office to obtain personal financial gain from the National Bank of Commerce in Birmingham, and for failing to disclose to the State Ethics Commission all of her outstanding loans for 1976.