This paper first proposes a new information slicing and transmitting method ITNC (information slicing and transmitting with multi-path network coding) with multi-paths network coding. Next, a novel anonymous communication mechanism AC-ITNC (anonymous communication mechanism based on ITNC) without key infrastructure, which is based on ITNC, is presented. In the new mechanism, the anonymous path setup information is sliced into pieces, and every piece is coded by the random coding coefficient. The coding coefficient and coded information pieces are delivered along different paths, which make the anonymous paths be set up in the case of non-cryptographic scheme. Theoretical analysis and simulation results show that AC-ITNC can significantly improve resistance against conspiracy attacks in an anonymous communication system within complete distributed environment without key infrastructure.