Chief Justice Warren E. Burger told reporters yesterday that the Supreme Court's heavy workload was in constant conflict with a project he has come to love even more than the law: planned celebrations for the 200th anniversary of the U.S. Constitution in September 1987.

Burger, who has guided the court for 17 years, has been chairman of the Commission of the Bicentennial of the U.S. Constitution since last year.

On the high court, he has been at the focal point of some of the nation's stormiest controversies. On the relatively obscure commission, the only controversy has involved whether meetings should be public.

The commemorative commission was established by Congress in 1983 to inform the public about the Constitution and its importance through history.

As Burger put it in an informal meeting with reporters:

"In recent weeks, it was becoming more and more apparent that I would have to retire as chief justice or resign as chairman of the commission. My first inclination was to resign as chairman of the commission."

But, he said he finally decided, "It's more important that we have an adequate celebration . . . than it is for me to be on the Supreme Court another few years."

"The bicentennial story is more important than my staying here," he said.

The commission, which President Reagan signed into law on Sept. 19, 1983, largely disappeared from public view until January 1985, when the White House picked former senator Roger W. Jepsen (R-Iowa) to plan activities.

Jepsen had lost his Senate seat after saying that, "in a moment of weakness," he had visited a Des Moines health club that had "nude encounters." Last summer, Reagan moved Jepsen out of that post, largely at the urging of Burger, who reportedly wanted to be the panel's chairman. He got the job in June and hired his court administrative assistant to be its $86,200-a-year executive director.

Burger yesterday expressed concern about the commission's slow start and inadequate funding. But, as one of its early successes, Burger noted the commission's work on the "Mini Page," a weekend newspaper cartoon supplement for children, in providing raw material for brief features on the Constitution.

"Then we're going to reach the high school kids, I hope," he said. He also mentioned prizes, "a law-school essay contest," and college symposiums and seminars.

In many ways, he said, "it's easier to be chief justice than to be chairman of the commission."