His primary scientific interests were history of serfdom and genesis of capitalism in the Russian Empire, but he also specialized in Russian medieval law and Byzantine law. Milov was a pioneer of cliometrics in Russia along with professor Ivan Kovalchenko and others.
Author of more than 150 works, in 1998 he published his opus magnum - Russian Plowman and Special Aspects of Russian Historical Process. Having conducted a thorough research of Russian agriculture and peasant life in the 16th and 17th centuries he argued that Russian serfdom as economical institute was a "compensational mechanism for survival". His works on Russian economic history are considered very important today. In last years of his life, Milov was in charge of creating a completely new textbook on Russian history based on post-Soviet science. The result was a book in three volumes written by a collective of historians. It was published in 2006.

• Anton Gorsky in the Memory of Leonid Milov
• A detailed biography on site of Faculty of History in Lomonosov Moscow State University
• Full bibliography from 1957 to 2009