In the article the theoretical bases of preventive and ecological maintenance of the armed forces are discussed. It is specified, that the main reason for preventive maintenance is preservation and strengthening of health and performance of the personnel, and for the ecological maintenance-achievement of ecological safety: preservation and restoration of the environment. As a result, protection of the personnel from the effect of the adverse factors is offered as a sub-gain of the ecological maintenance, and a sub-gain of preventive maintenance is the control of the environment protection, which defines the health state of the personnel.