The Supreme Court agreed yesterday to decide whether a state can commit a person to a mental hospital - possibly for life - without proving beyond a reasonable doubt the need for the commitment.

"There is no rational basis for a rule that would require less caution in an indefinite civil commitment than in a criminal or juvenile proceeding," lawyer William Allison of Austin, Tex., argued in a successful petition for review of the case of Frank O'Neal Addington.

After a jury trial, a Galveston County, Tex., court in February 1976 committed Addington indefinitely to the Austin State Hospital on the ground that it was necessary for his welfare and protection as well as for others. In doing so, the court said it was acting on "clear, unequivocal and convincing evidence" as required by state law.

An appeals court reversed on the ground that the need for commitment had not been established beyond a reasonable doubt. But the intermediate court was upset last October by the Texas Supreme Court, which held that the correct standard of proof was the lesser one applied by the trial court.

The Supreme Court yesterday took other actions: Drunk Drivers

All 50 states empower police officers to threaten drivers suspected of being drunk with suspension of their operator's permits if they refuse to take a breath analysis or other test to determine if they are intoxicated.

Of the 50 states, however, only 13 do not provide for a hearing before suspension. One of the 13 is Massachusetts, which provides for a hearing promptly after suspension.

Two years ago, after a collision, Acton, Mass., police asked Donald E. Montrym to take a breath-analyzer test. He refused. A few weeks later, stake authorities suspended the driver's permit of Montrym, who was charged with driving under the influence of intoxicating liquor.

He claimed, and a lower court agreed, that he had been denied due process of law in violation of the Constitution. The Supreme Court will hear the state's appeal.