This paper analyzes the system capacity of the cdma2000 and then provides a conclusion about the relationship between the data ratio adjustment and the system capacity.For the first time

introduce the service time into the system capacity.Consider the integrated influence of the data ratio and the service time and propose the evidence and scope of the ratio adjustment.The proposed conclusion proves that the system capacity is not always increased with the decrease of the data ratio.Thus it correct the error of the conventional notions.The simulation results show that selecting the data ratio based on the theoretic conclusions could minimize the Outage probability and then get the maximum system capacity.