【摘要】The message that expressed by dividend policy is very abundant. Under strict assumption,dividend policy is irreverent with corporate value.But under information asymmetry condition, dividend distribution is relevant with stock price,which will cause the corporate actual investment level lower than the optimal level of Fisher standard, but the proportion that distributed actually higher than the optimal level of Fisher standard. So when the corporation makes dividend policy decision, it should consider the balance between the extra tax expense produced by the dividend and the signaling and free cash flow effect due to dividend distribution commitment.