Studying the problem of the relationship between the principle of partisanship and natural science is an urgent task in the fight against bourgeois ideology, with various concepts of "deideologizing science." The work shows the essence of Lenin's understanding of the principle of partisanship in its relation to scientific knowledge. The following aspects of this principle are disclosed: socio-political, worldview-epistemological, general methodological and moral-ethical. It identifies, in particular, the role of class useful assessments in relation to the choice of scientific information and outlines the scope of these assessments in the field of natural science. The work also criticizes the left-populist concept of "socialization of science."