The method, TS/FM (Time Step/Frequency Mode), is employed with fixed time step to analyze performing techniques of 'An' and 'Zhan' on the pitches of 'Yi-Fan' of Hakka Zheng work 'Lotus Emerging out of Water'. By acoustic measurements, we analyze the tone frequency of the performance of Ning-xin Rao, a master musician of Hakka Zheng music. The study shows performances by the same musician at various time and in different places however exhibit many similarities but still contains variations which characterize the changing frequency on the pitch of 'Yi-Fan' of Hakka Zheng music.