In this study, we tried to heighten recycling rate of fly ash that become amount used limitation. For this, variables decided by the fly ash substitution amount, agent amount of PCA superplasticizer and unburned carbon content, and investigated change of air content and fluidity etc. by each variable. As the results, decrease range of fluidity and air content was the biggest in case of 8% more when unburned carbon content is 3 - 5% range. But, the result displayed that air content of cement mortar is admonishing proper level in case of unburned carbon content 8%. From result of above, this study got conclusion that can expand enough practical use extent of fly ash that is limited strictly by present unburned carbon content 5% low.