In this paper, we study the effect of channel estimation error at the receiver on the mutual information of a multiple-input-multiple-output (MIMO) channel obeying correlated Rayleigh fading. The system model is constructed based on the channel estimation error at the receiver side. And using the properties of Wishart distribution, the lower bound on the channel capacity is derived when the MIMO channel is full rank. The simulation results show that the channel capacity of MIMO system is sensitive to the channel estimation error. The channel capacity is maximized when the signal-to-noise increases to a certain point.