Abstract: For researching browning of tissue cultured-seeding of Phalaenopsis aphrodite Rchb. F. it has been judged the influence of PPO gene and PAL gene by observing the expression of tissue culture time differently of Phalaenopsis aphrodite Rchb. F.. We obtain the target sequences of PPO gene and PAL gene by designing specific primers and test the expression of the above mentioned genes by real-time PCR. In our study , the similarities between Phalaenopsis aphrodite Rchb. F. PPO and Phalaenopsis aphrodite Rchb. F.× pulcherrima PPO are up to 97% and the similarities between Phalaenopsis aphrodite Rchb. F.t × Doritis PAL are up to 98%.We find that after slicing the leave of tissue cultured-seeding, the expression of PPO dramatically increases, and as time goes by, the expression first slowly descends and then increases. The expression dramatically increases between 10d and 12d and then is up to the maximum, at last the expression is lower and not change much; The expression of PAL gene rapidly increases, respectively 1d,8d and 12d ,and the expression is the maximum at 12d.At last, the expression is down. The expression receive maximum at 12d both PPO and PAL, which has been illustrated that it is the critical period for browning. Only taking precaution at that time , can it increase browning.