This paper discusses the relation between mandatory management earnings forecasts and real earnings management and this paper find some evidence and collated some literature. This paper find evidence, first, if Japanese firms have upwards MEFs, then have using real earnings management. Second, if Japanese firms revise more cumulative amount of the MEFs, then the Japan’s firms would give up revise MEFs rather than revise financial forecast directly. Third, if Japan’s firms have wider gap between initial forecasts and realized earnings, the Japan’s firms would give up revise MEFs too and revise financial forecast directly. Besides, this paper provided additional tests to get step further research on multiply relation of hypothesis. Key words: Mandatory earnings forecasts, real earnings management