This article base on the data of Fisheries Department from 82 to 96 discussed the resources of Taiwan mackerel. First of all, Leslie¡¦s method is used to estimate the stock size and catchability coefficient of Taiwan mackerel from 90 to 91. The consequent went under the method of Graham in order to estimate its intrinsic growth rate and environmental carrying capacity. Following that, this paper compared and contrasted the differences between open access and bioeconomic optimum, and adopted the catch data of 82-96 to get the simulative analysis of present operation of mackerel. Finally, for each parameter we made sensitivity analysis to have an overall view of the impact of changed parameters on stock size.