Research efforts have been put into content retrieval in the Internet, ranging from traditional web proxy to recent content-oriented network architectures. With the emerging trends of uploading large user-generated content, we argue that Internet should not only aid end users in downloading content from steadily available servers but also facilitate uploading content. In this paper, we propose upload cache in edge networks, a new edge-network mechanism assisting upload of user-generated content (UGC). Our proposed mechanism brings benefit for both end users and service providers. For end users, it shortens the duration while user must stay online for uploading their generated content. Also for service providers, it reduces peak traffic volume between edge networks and data centers by slightly shifting the upload timing without incurring much extra latency overhead added. Our analysis with replaying the captured traffic shows that this mechanism reduces upload tether time of 24% end users by more than half and flattens the traffic peak for the access service provider by 37%.