Abstract: In order to predict coke properties, then to blend coals for coking, based on Ammosov-Shapiro coal petrographic analytical method, the fuzzy set coal bl ending method was put forward. The classification of activity component and inert component has been used.Figures of 'Optimum ration of reactive to inert for each vitri noid type and'Relationship of rank index, Inert and vitrinoid type of coal'have been adopted. Sets of pseudo strength index PSI and pseudo component balance index P CBI have been created. The calculation formula of elements and the transformation from elements to strength index SI and component balance index CBI have been de fined. The study show that the linear additive characterization of coal macerals through PSI could be used to regress and predict the coke quality. According to the resul ts of 55 data regression, the maximum relative error of coke reactivity index CRI is 4.8%，the average relative error is 1.6%.The drawings of four iso-coke properties ha ve been attained. Both the regression equation and the drawing of iso-coke property can be used to predict the coke property.