A remarkable collection of Cycladic figurines and vases -- the oldest made 2,000 years before the fall of Troy -- will go on view May 20 at the National Gallery Of Art.

This is the first large exhibition of antiquities from Greece over to be sent to the United States.

All 166 objects to be shown here are drawn from the collection of Mr. and Mrs. Nicholas Goulandris. Their fortune comes from shipping. They began to buy Cycladic art less than 20 years ago. Their collection, though it cannot match that of the Greek museums, is probably the finest now in private hands.

The grave goods of the Cyclades, a group of islands at the center of the Aegean Sea, look, despite their age, peculiarly modern. No one knows the function of these small marble statues. Their harmoniously proportioned, strangely abstract faces somehow bring to mind a Bronze age Brancusi.

The oldest of these figurines, with their violin-shaped bodies, have narrow waists, wide hips, and long and headless necks. They appear to be descendants -- no one knows for sure -- of the far older "venuses" of neolithic art.

Between 3,500 and 2,000 B.C. the people of the Cyclades developed a sophisticated civilization. They used bronze for their spearheads and copper for their daggers. If they had a written language it has not survived, but they were skillful seafarers and they masterfully worked marble.

Of their later statues, perhaps nine of 10 depict the nude female figure. She is usually reclining, her arms crossed at her waist, or across her breasts. Her long Grecian nose is frequently the only three-dimensional feature of her face -- though traces of old red and blue paint remaining on some statues indicate her hair, her headdress and her eyes.

The few surviving male figures depict cup-bearers or hunter-warriors or musicians playing lyres. A number of these statues have been sculpted in the round.

Patricia Getz-Preciosi of New Haven a Harvard-trained archeologist who has studied the collection, says its most important pieces are a white marble vase in the shape of a pig and a seated male cup-bearer that is the only complete statue of its kind that has managed to survive.

Later Grecian carvings, those of Crete and the "Archaic" period and of classical Greek art, seem to have developed from Cycladic art.

Mr. and Mrs. Goulandris have assembled their collection with the permission of their government, with the understanding it would not be sent abroad. That restriction was lifted for the first time in 1977, when the government of Greece passed a law permitting Greek antiquities to be lent overseas.

The Egyptians and the Chinese already have sent to Washington collections of antiquities. The Greeks are following suit. "the Search for Alexander," a government exhibition dealing with the life of Alexander the Great will open here next year at the National Gallery. It will include recent finds, some of them of gold." "Art of Greece," another exhibition, this one drawn from the collection of the National Archeological Museum in Athens, is now being planned for New York's Metropolitan Museum of Art.

"Cycladic Art: Ancient Sculpture and Ceramics of the Aegean (3500-1-500 B.C.) from the N.P. Goulandris Collection" will remain on view all summer in the Gallery's East Building. It will close Sept. 3.