AtERFA (ethylene response factor) is a negative regulator in jasmonic acid mediated signal transduction pathway and ethylene mediated signal transduction pathway of Arabidopsis. It could respond to abscisic acid (ABA) and ethylene stimulus. ATSYRX gene encodes a syntaxin localizing at the plasma membrane in Arabidopsis, which can be induced by abiotic stress. To identify mutation lines for gene functional analysis, real-time PCR was employed to detect the expression level of AtERF4 and ATSYRX in homozygous T-DNA insertion mutant line, respectively. Real-time PCR is a powerful tool which can be used to detect steady-state mRNA levels specifically, sensitively and reproducibly. Comparing to other forms of quantitative RT-PCR, the amount of amplified products can be detected by real-time PCR instantly and thus is a preferable alternative. In this study, RNA with T-DNA inserting into exon could be detected in At ERF4 knock-out mutation line. The results indicated that AtERF4 had been trucked in transcription level. On the other hand, T-DNA inserting into the promoter of gene ATSYRX had no effect on reducing the expression level of ATSYR1 gene. Further molecular and phenotype studies now are ongoing to clarify the potential consequences of AtERF4 and ATSYRX deficiency in Arabidopsis.