Prince George's County Executive Winfield M. Kelly Jr. is trailing Republican challenger Lawrence J. Hogan by a small margin in his reelection bid, according to a combination of two separate polls of county voters taken recently for Kelly.

Kelly, a Democrat, told members of the county police political action committee Thursday that the combined totals of the two polls show him slightly behind Hogan, the former congressman.

The first poll taken in May, consisted of a detailed questionnaire that was sent to a random sampling of about 400 county voters, including both Republicans and Democrats, according to Kelly aide John A. Lally.

The second poll, which contains only three questions, was sent to "thousands" of registered Democrats during the past month, Lally said.

"Actually I'm very pleased to be where we are now," Kelly said. "The survey in May showed us trailing badly. According to this poll, we're closing ground well. I'm confident that we'll overtake the congressman."

The May survey was one of a series of polls taken every six months during Kelly's administration "in order for us to get a reading on what people were thinking," Lally said.

The more recent survey consists of three questions: How do you feel about Winfield Kelly? Why do you like/dislike Kelly? Who do you prefer right now, Hogan or Kelly?

Sources said the two surveys showed Kelly trailing in the northern area of the county and doing better in the more rural southern portion.

Kelly is being opposed in the Sept. 12 Democratic primary by John Eugene Sellner, John L. Ball Jr. and Vincent Goodsell, none of whom are considered threats to upset him.

Two opponents are challenging Hogan for the Republican nomination, Martin Aragona and Dale D. Everett, but the former congressmen is a heavy favorite to win his party's nomination.

Hogan spokesman Lou Helm said yesterday that a poll of 400 county residents conducted for Hogan last week showed the Hogen's name was recognized by twice as many voters as Kelly's. The name recognition problem is a major concern in the Kelly camp, sources say.

"I have complete confidence in our poll and our lead." Hogan said, "We have a solid lead and I'd be willing to make our poll public if Kelly's people will do the same."

Lally said that Kelly "won't get into a polling war" and added that he would not release poll results on "general principle."

Apparently concerned over poll results. Kelly agreed to meet on July 28 with Fraternal Order of Police President Laney Hester. The two have been at odds for several months over a number of issues, most notably the police department's new contract.

According to sources, Kelly is extremely troubled by the closeness of the race and met with Hester in a last-ditch effort to salvage the police endorsement or at least persuade the police not to endorse anyone in the county executive's race.

The effort failed, sources said, and the only question now is whether the police will endorse Hogan this week or after the Sept. 12 primary.

Kelly said he was not conceding the police endorsement to Hogan as this point. "I guess it's fair to say that in a race that's going to be as close as this one any endorsement is important," he said.

Kelly said he thought that Hogan's popularity stems from his three terms in Congress where he served from 1968 to 1974. "I think he still has a very high degree of visibility dating back to his days in Congress and that's an important factor this early in the campaign," Kelly said. "Name recognition is a great thing to have but I think as the campaign evolves it will take more than that alone to win."