The call processing capacity of a base station in CDMA cellular network can be changeable due to the additive loads from handoff, paging and location registration as well as call setup/release. In general, the load box test is widely used for measuring the call processing capacity of a exchange in the fixed network. But, it is difficult to estimate the processing capacity accurately because system load includes hand-off, paging in a mobile network. In this paper, we propose a new methodology for the calculation of call processing capacity to investigate the effect of traffic parameters on the system capacity, through the traffic modeling of call flow in base station. This result shows that the traffic load of hand-off limits the system capacity largely and is more severe than has been expected. Regression analysis will be also derived for the investigation of unit load and linear relation between CPU load and traffic load. This analysis using the field data from an operating site indicates that the call processing capacity in the wireless network must be specified with the rates of hand-off, paging and location registration, in contrast with the fixed network.