Vibration pathology is in the second place among diseases connected to the profession. The vibration effect both on the protein fraction shifts and on the activities of I type arginase (Arg) IA and IB from white rat liver has been studied in the conditions of 5-, 10- and 15-day vibration state. In the initial state of vibration some decrease of Arg IA and Arg IB activities was revealed as compared to the control without general protein spectrum change of liver extract. Along with vibration effect, the expression level of Arg IA was increased with duration enhancement, which possibly is due to hyperammonemia, in the result of which ureagenesis is stimulated. Stimulation of easy available adaptation reserves were described due to protein catabolism. Analysis of shifts of general and enzyme protein fractions in the conditions of vibration effect allows to reveal their qualitative and quantitative changes and to make important the organism adaptation reactions that result from anabolic and catabolic process relations. It is possible that the revealed changes in the activity of arginase IA and IB are a biologically expedient mechanism for regulating the activity of hepatic arginase during vibration stress.