Abstract: A multi-channel and multi-service random multi-access protocol with double clocks and two dimensional probability was presented.The control clock was designed by combining slot access and consecutive time access together.The choice of the two parameters and was adopted to study the random system with multi-channel and multi-service controlling.Due to the advantages of slot access combining with consecutive time access,the performance of multi-channel and multi-service random multi-access protocol with double clocks and two dimensional probability was improved.Furthermore,it analyzed the systemic throughput of MMDCTD protocol.The results show that the simulation is in concordance with the theoretical analysis.In other words,the comparing results with slotted-time and continuous-time CSMA system show the mixed system is better.