The sculptors are coming.

Some 4,000 sculptors -- a number of them famous and a few of them accompanied by monumental works -- will arrive in Washington next spring for the 11th International Sculpture Conference, which opens here June 4.

Ten of them plan to place their art along the Baltimore-Washington Parkway; their sculptures will be big enough that passers-by can read them from moving cars.

Claes Oldenburg, the pop artist whose colossal baseball bat stands on end in Chicago, will bring to this city a 40-foot-high trowel, which he plans to stick point-first into the rubble of a construction site downtown.

Isamu Noguchi, the conference's honorary chairman, will be represented by carved stone from Japan; it weighs 14 tons. Huge mylar balloons -- and a laser piece by Rockne Krebs -- are expected to be placed in the air above the Mall.

Effi Barry, the mayor's wife, announced the conference yesterday morning, and the participants she listed seem a Who's Who of the art. Among those coming to talk, work and show here are Louise Nevelson, Tony Smith, Ron Balden, Alice Aycock, Larry Bell, H. C. Westerman, Nancy Graves, Vito Acconci, George Segal, Richard Serra and Sol Le Witt.

Robert Irwin, whose sculpture is so subtle it sometimes seems invisible, will do a large new peice downtown. Ed Keinholz, whose attack-the-eye assemblages are not easily forgotten, will show his work. So will Yuri Schwebler, Martin Puryear, Ed Love and Anne Truitt -- local artists all.

The previous two biennial conferences, in New Orleans and Toronto, were both successes. This one will have a budget of $800,000 from the meeting's sponsor, the International Sculpture Center, Inc. -- a privately endowed Princeton, N.J., group that promotes and fabricates sculpture. ISC officials say they'll raise the money, but the cash is not in hand.

They are seeking $100,000 each from the National Endowment for the Arts and the Humanities Endowment. Participants will pay a registration fee of $90 (rising to $115 after Feb. 1). Students will pay less: $15 now, $70 later. Conference director Christine Reed says she is "certain" that foundations, corporations and assorted private "angels" will provide the needed cash.

The International Sculpture Center was established in 1956 by Prof. Elden Tefft, a sculptor who had helped establish a new bronze casting foundry at the University of Kansas in Lawrence. The first conferences were held there, but in time they grew too large for the university to support. In 1978, the Center moved to Princeton, where it merged with the Johnson Atelier Technical Institute of Sculpture, a studio for fabricating sculpture headed by J. Seward Johnson Jr. (heir to the Johnson & Johnson family fortune), a sculptor and philanthropist who has since picked up many of the Center's bills.

The first sculpture conference was held in 1960 at the University of Kansas. It was a technological convention at which participating artists discussed molten metals, casting, patinas and similar subjects. The theme of the New Orleans meeting of 1976 was monumental sculpture; the 1978 conference in Toronto dealt with general concerns.

The four-day Washington conference will include many panels, workshops and discussions; the Park Service has agreed to let the conferees show work on the Mall. Sculpture exhibitions also will be held at the Pan American Union, the Washington Project for the Arts and other local galleries. It is only coincidental, but the Union Internationale de la Marionnette and the Puppeteers of Ameria also will be meeting in Washington next spring. Puppets are sculptures, too.