Abstract: Ascorbate peroxidase (APX) and S-adenosyl methionine synthetase (SAMS) play important roles in plant stress response. To study the relations between the two enzymes and poplar disease resistance, the poplar high resistant clone “NL895” was used as the experimental materials and then the expression changes of them at mRNA level after different times of pathogen infection in poplar leaves were analyzed utilizing the real-time RT-PCR. The results showed that the two enzymes were both differential and dropping expression. It indicated that they were closely correlative with poplar disease resistance. It was found that the expression changes of APX and SAMS at transcriptome and proteome levels had no significant correlations by further comparing the expression ones.