With the development of the Internet, stimulating users knowledge creation that is in favor of enterprises in virtual brand communities has become the key for enterprise to implement innovative strategies in order to respond to dynamic market conditions.In this paper, we have built a theoretical model, which can motivate enterprise knowledge creation, based on the perspective of users exploratory/exploitative learning and ideation portfolio management in C2C and B2C virtual brand communities.Our Empirical findings are as follows: C2C and B2C virtual brand communities have variant impact on users exploratory / exploitative learning. With respect to B2C virtual brand communities that are beneficial to users exploitative learning, C2C virtual brand communities tend to inspire users exploratory learning, which is more conducive to stimulate users knowledge creation capability.However, users knowledge creation capability has no significant effect on generating enterprises knowledge creations. Furthermore, users ideation portfolio management plays a mediating role between them and the influence is positive and significant.This study has put forward valuable revelations for companies to carry out the strategy of user knowledge management innovation.