STANFORD, Calif. (AP) _ Notes written in invisible ink, photos of bodyguards and other documents associated with Russian revolutionary Leon Trotsky have been discovered by the Hoover Institute on War, Revolution and Peace.

The find, which would form a pile 30 feet high, was reported in the latest issue of the American Historical Review by Dale Reed, an assistant archivist at the institute, and colleague Michael Jakobson.

Trotsky played a leading role in the November 1917 seizure of power by the Bolsheviks and organized the Red Army during the subsequent civil war. He lost a power struggle with Josef Stalin, and in 1929 was banished from the Soviet Union.

Trotsky spent his life in exile, writing books that served as inspiration to anti-Stalinist Communists. He met his end in Mexico City in 1940 at the hands of a purported Stalinist agent who smashed his head in with a climbing tool.

The papers were found in a collection willed to the institute by Boris Nicolaevsky, a Russian emigre and historian who lived in the San Francisco Bay area and died in 1966.

The collection was left to Hoover on condition that Nicolaevsky's widow remain curator of the papers. Archivists looking through it after her 1982 death discovered the Trotsky papers.

The collection includes an early draft of Trotsky's 1928 attack on Stalinist aides who had called for him to halt ''counterrevolutionary'' activities. It was written in the margins of a book in invisible ink that later became visible.

The collection includes a chapter, left out of Trotsky's many books, on events after the revolution. Reed said the material will be of great historical interest to scholars.

Also among the papers is a letter Trotsky's son and political collaborator, Leon Sedov, wrote to his mother, Natalia Sedova.

''I think that all dad's deficiencies have not diminished as he grew older, but under the influence of his isolation (which is) very difficult, unprecedentedly difficult, (have) gotten worse,'' Sedov wrote. ''His lack of tolerance, hot temper, inconsistency, even rudeness, his desire to humiliate, offend, and even destroy have increased.''

Sedov never mailed the letter.

Many of the papers ''show us the human side'' of Trotsky, Reed said. ''There are several letters in which they discuss the practicability of Sedov purchasing a dog and sending it to (Trotsky) in Turkey, where he was in exile. ''Others refer to very poignant things such as his (Trotsky's) daughter's suicide,'' he said. ''She left a small child, and Trotsky felt great anxieties about what would happen to him.''

Trotsky outlived his children. His daughter committed suicide, one child died of tuberculosis and Sedov died in 1938 during minor surgery in Paris, Reed said. Another son disappeared in the Soviet Union, possibly a victim of a Stalinist purge.