Empirical researches have showed that the liquidity and default risk are correlated in financial markets．However，traditional corporate bond pricing seldom considers this risk correlation even when the market is affected by default significantly． In this paper，we introduce both liquidity and default risk into a unified framework． Based on this expression，we extend the reduced form model by considering the correlation between liquidity and default risk． Theoretical derivation，numerical results and the empirical results based on corporate bond data in Chinese market show that there is a positive correlation between liquidity and default risk，which has a quite important effect and interaction on the spread of corporate bonds．