Floyd Keith, 30, an assistant coach the past five years at the University of Colorado, is expected to be named Howard University's new football coach this week, it was learned last night.

"That's a little premature," Howard Athletic Director Leo Miles said. "We have not hired a coach. We will make an announcement at an appropriate time. Until then, we don't have a coach."

Keith, who has no previous headcoaching experience at either the high school or college level, will replace Doug Porter, who was fired Dec. 15 affter criticizing university support of the team. Porter compiled a 30-21-1 record in five seasons, with 4-6 in his last compaign being his only losing year.

According to sources, all that remains for Keith to be offered the job is approval by Howard President James Cheek of a recommendation submitted by a selection committee.

A Howard souree said Keith was picked as the No. 1 candidate because of his organized presentation in an interview last week. It was learned "five or six" candidates were interviewed from a field of about 40 applicants.

Keith is scheduled to return to Washington from Boulder, Colo., today and meet with Cheek for the first time.Unless something unforeseen happens then, Keith's approval is considered a formality.

He coached the passing game last season at Colorado under Bill Mallory, who was fired after the season and whom the Buffaloes hope to replace with Chuck Fairbanks, coach of the NFL's New England Patriots.

A native of Lima, Ohio, Keith won all-league and all-state honors at St. Mary's High School there, graduating in 1965. He won eight letters in football, basketball and track. He went to Ohio Northern University where a knee injury in his sophomore season ended his playing career.

He received his BS degree in physical education from Ohio Northern in 1970.He began his coaching career as an assistant coach at St. Mary's and as an Ohio Northern scout in 1968 and 1969.

He joined the Miami of Ohio staff in 1970 as receiver and windback coach and then coached tight ends and receivers for Mallory there until joining the Colorado staff in 1974.

At Colorado, Keith was described by a colleague as the easiest-going coach on a very intense staff. He is an extrovert and relates well to players, the source said.

He was known as a good recruiter for the Buffaloes, with Southern California as his primary area. Among his better-known recruits was Tony Reed, now a star running back for the Kansas City Chiefs.