The content of lactic and pyruvic acids in the brain was studied as affected by heavy mechanical trauma. It was established that under the trauma effect the content of lactic acid in the brain tissue increases and phase changes are observed in the content of pyruvic acid and in the value of the lactate pyruvate ratio. Lactic acid accumulates most intensively in the cerebellum, cortex and subcortical areas of the brain, and less intensively--in medulla oblongata and spinal cord.