This paper presents an experimental research on the collision transition between two upper levels of copper atom with an oscillator-amplifier chain of copper vapor laser. In this experiment, the phenomenon of this kind of collision transition in case of high buffer gas pressure was observed through the comparison of laser pulse waveform which was obtained when different oscillation laser was fed into amplifier. Therefore, the existance of this kind of transition was proved by this experiment. The mechanism of this kind of transition is also dicussed.