We use the natural experiment method to study the relationship between financial constraints and corporate information disclosure.We took 2004 VAT reform in northeast of China as an exogenous shock which relieved financing constraints，the study found that the corporate information disclosure quality decreased significantly after the event.Financing constraints are positively related to information disclosure.We separated high financial constraints and low financial constraints by ownership of enterprises，KZ index and SA index.We found that the positive relationship between financing constraints and corporate information disclosure were stronger in the state owned enterprises and high financial constraints enterprises，which means that enterprises in financing constraints before the event would adjust themselves more.The relationship between financing constraints and information disclosure is based on the theory of asymmetric information；enterprise information disclosure policy would consider the information disclosure and financing costs.When financing constraints eased，the corporate financing pressure decreased and reduced the quality of information disclosure.The conclusion of the positive relationship between financing constraints and information disclosure is one of the important factors that affects the information disclosure，which can also be used as a reference factor when making information disclosure policy.