Abstract: Traditional learning/instruction of management accounting is not accordance with the requirements of actual business operation and management condition. This research aimed to develop an innovative instruction tool named as process phase situated interactive on-line learning/instruction platform which was developed particularly for effective learning/ instruction of management accounting in order to conform the requirements of actual operation management under dynamic multi-dimensional cross-related condition. In addition, an instruction material named as process phase situated role-play practice was developed as well which was applied together with process phase situated interactive on-line learning/instruction platform. The innovative value of this research solves the disparities between traditional learning/ instruction of management accounting and the requirements of actual business operation and management: • Operation management situation simulation under dynamic multi-dimensional cross-related business condition • Process phase situation simulation of continuous optimization of management accounting • User-friendly human-machine interface for manipulative setting of multiple situations autonomously • Learning/instruction/application-in-one on-line platform • Automatic data streaming and calculation • User-friendly human-machine interface for visional express feedback and interpretation • Instant messaging interactive communication platform between instructor and learners Keywords: Management Accounting, Process Phase, Situated Role-Play, On-Line Learning/Instruction, Instant messaging about four key words separated by commas