Test on creep of recycled coarse aggregate concrete(RAC) was conducted by varying the recycled coarse aggregate(RCA) replacement rate(0%, 50%, 100%). Base on test results, split phase research method was adopted to study the interaction mechanism among natural aggregate, old adhered mortar and new mortar in the creep process of RAC for the high values and large discreteness of creep of RAC. Thus creep mechanism of RAC was revealed and creep prediction model of RAC was established. The results show that specific creep of RAC increases with the increases of RCA replacement rate; the influence of creep and content of old mortar on creep of RAC is significant; reduction of the creep and content of old mortar are effective way to realizing low creep of RAC; and the comparison between test values and prediction values indicate that the prediction model can predict creep of RAC well.