Two emission bands of Zn2 excimers have been observed in mixture of Zn vapor and buffer gases by optically pumping Zn (4s1S0—4p3P1) resonance line. Expe rimental evidence shows that they are possibly from the same 3∑u+ upper state of Zn2 excimer, this coincides with theoretical prediction. Their temporal and temperature behaviors, and also the effect of buffer gases were studied. The upper limits of molecular formation and quenching rate were determined separately. The rescults indicate that the buffer gases dominate the molecular formation and decay process.