Abstract: Through comparing the economic performance of implementing safety investment activities and the economic performance of non-implementing safety investment activities, economics principle is used to identify the factors which influences inadequate investment for safety. The results show that the factors which influence inadequate investment for safety mainly consist of the punishment extent of illegal act, the compensation of coal mine enterprise by accident and the probability of illegal act for supervision department discovering. Finally, in view of the above three factors, the paper proposed some policy suggestions to inspirit coal mine enterprises increase safety investment.