Shadr's early works, such as the project for the Monument to the World's Suffering (1916), were designed according to the principles of Art Nouveau.

After the 1917 Revolution he was an active participant in the execution of the Monumental Propaganda Plan, in particular, he sculptured reliefs depicting the Socialist ideological leaders Karl Marx, Karl Liebknecht, and Rosa Luxemburg, as well as some sixteen separate monuments to Vladimir Lenin.

In these years the characteristics of Shadr’s style were consolidated: an elevated, romantic organization of the figures and an emotional, dynamic composition.

Among his most famous and characteristic works are sculptures The Cobblestone Is the Weapon of the Proletariat (1927) and Girl with an Oar (1936).

In the 1920s, Shadr together with sculptor Piotr Tayozhny came up with one of the first designs of the Order of Lenin, the highest Soviet award.