Based on 11718 acquisition events data during 1999 - 2009 in Chinese listed companies, the positive study results show that the severer the tunneling behavior, the worse the performance of the company. Tunneling of all samples prior to the acquisition is significantly higher than that after the acquisition , indicating the behavior of tunneling of these listed companies weakened after the acquisition. The group with the lowest level of tunneling has a negative wealth effect of shareholders after being acquired, nd the group with the highest level of tunneling has a positive wealth effect． Regression analysis found that the greater the degree of separation of control rights and cash flow rights is, the greater the negative impact of tunneling on performance; the smaller the degree of restriction of the block shareholders，the smaller the negative impact of tunneling on performance; if the position of chairman and general manager is occupied by the same person before being acquired, the wealth effect will weaken after the acquisition to improve tunneling; the greater the degree of the separation of control rights and cash flow rights in the target company before the acquisition，the smaller the wealth effect of the target company is．