This study is attempted to serve the fundamental theory for ‘The reorganization of Korean coastal and adjacent water fishery.’ On the Korean coastal and adjacent water fishery where one species stock is catched by multiple fisheries, traditional analysis is not suitable, as analyzing through adjusting the heterogeneous fishing effort among the fisheries to an unit having same fishing strength. Therefore, this study presents the ‘Multi-Variable Model’, adopting fishing effort from each fishery as independent variable, respectively, in order to analyze the quantitative fluctuation of fishery resource not with fishing strength but with amount of fishing effort, measured by the unit of each fishery. For the sake of simplication, this study assumes that one species is catched by two fishery, premise two assumption. 1) Every fishery has not the selectivity in fishing 2) The promotion of fishing efficiency is accomplished in the same speed. Resource equilibrium equation of each fishery is; $$CPUE_1=frac{Y_1}{E_1}=a_1+ b_1cdot E_1+c_1cdot E_1$$ $$CPUE_1=frac{Y_1}{E_1}=a_1+ b_1cdot E_1+c_1cdot E_1$$ Sustainable yield equation is; $$SY_1=a_1cdot E_1+cdot b_1E{_1}{^2}+c_1cdot E_1cdot E_1$$ $$SY_1=a_1cdot E_1+b_1cdot E_1cdot E_1+c_1cdot E{_1}{^2}$$ This study is rudimentary, hereafter, refinemental analysis will be supplemented.