It is known that the addition of methanol to the culture medium stimulates the photosynthetic productivity of some species of microalgae, but its influence on the biochemical composition of the biomass has not been investigated. The aim of the present work is to determine the effect of methanol (50 mM) on the content of free amino acids, soluble proteins and reduced nicotinamide coenzyme NAD(P)H in C. reinhartdii cells. It is shown that in case of illumination of C. reinhardtii methanol raises intracellular content of NAD(P)H four times more efficiently than in the darkness. Total content of free amino acids is increased and their ratio is changed. The concentration of glutamic acid, glutamine, alanine, serine and tyrosine also increases. The concentration of valine and methionine is reduced. Growth of culture with methanol is followed by an increase in the content of intracellular protein by 30% after 20 hours of cultivation. The obtained data indicate that methanol stimulates growth of C. reinhardtii, not only as a result of additional carbon utilization, but also due to improved nitrogen assimilation and the impact on the energy metabolism of cells.