Budget Execution Auditing is designed to discourage the opportunism of budgeting. However, if it is arranged inappropriately, it may encourage manners of budgeting opportunism. According to the theoretical study, the effects of government auditing on violation of budgeting are decided by a combination of discovery rate, treatment rate and penalty rate in budget execution auditing. Among these rates, penalty rate is the key variable. Public sectors make their strategic decisions of budget violation based on these three rates. After analyzing the data of budget execution auditing, we found that budget execution auditing actually encouraged the violations of budget instead of its being discouraged, because the threatening power of penalty is not enough.