Embodiments of the invention provide a method and device for establishing uplink (UL) synchronization. The method includes: instructing a UE to perform a dedicated PRACH transmission; calculating a timing advance (TA) according to first timing information derived by itself and second timing information received from a plurality of non-serving base stations, and sending the timing advance to the UE to enable the UE to establish the uplink synchronization with involved base stations according to the timing advance, wherein the first timing information and the second timing information are associated with propagation delays of the dedicated PRACH transmission performed by the UE. With the above solution, it may be easy to establish UL synchronization between the UE and all involved base stations for UL CoMP.