The boom of M&A has exacerbated goodwill bubbles.Using a sample of Chinese listed companies，this paper finds that CSR fulfillment can effectively inhibit the goodwill bubbles.It arrives at the conclusions as follows:good CSR performance can reduce goodwill and decrease the excess goodwill，which is more significant in non-state-owned enterprises.The intermediary effect research shows the influence mechanism:CSR fulfillment restrains goodwill bubbles by enhancing reputation and improving information transparency.Further research finds that voluntary disclosure can exert an inhibitory effect.The fact that high internal control quality can strengthen the inhibitory effect is more obvious.According to the paper，the research shows that CSR fulfillment，as an effective governance mechanism，plays the function of signal transmission and reputation constraint，and improves the fairness of goodwill valuation，thus restraining goodwill bubbles，and reducing risks and maintaining market stability.The conclusion suggests that voluntary disclosure is more effective than mandatory disclosure.Therefore it is necessary to cultivate internal governance environment and external institution so that the corporate can actively fulfill their social responsibilities.