In three experiments on white rats and in two experiments on volunteers variations of 20 clinical and laboratory parameters were investigated upon an exposure to impact accelerations. The results demonstrated a correlation between changes in the general state of the animals and morphology of viscera, on the one hand, and changes of hematological and biochemical parameters, on the other. A scheme of utilizing more informative parameters for the in vivo differentiation of effects of impact accelerations is recommended. Manned experiments indicate that measurements of urine excretion of endogenous creatinine hold promise for these purposes.