Phenylalanine ammonialyase (PAL) is encoded by a multigene family and is the starting enzyme for the synthesis of polyphenolic substances such as anthocyanins, and PAL has a regulatory effect on anthocyanins synthesis. The Gateway technology system was used to construct the tea plant CsPAL3 overexpression vector pGWB502: CsPAL3 and pGWB505: CsPAL3: GFP from purple leaf tea cultivar Wuyi qizhong C18 (Camellia sinensis), and successfully transferred into Agrobacterium tumefaciens GV3101. By transient expression of the injected tobacco, GFP green fluorescence was observed by laser confocal scanning microscopy, indicating successful transient expression, and the results showed that the CsPAL3 is mainly concentrated in the nucleus and cell membrane. Through invading Arabidopsis thaliana, the homozygotes were screened to obtain stably expressed transgenic CsPAL3 A. thaliana. The expression of CsPAL3 in the transgenic CsPAL3 gene A. thaliana was significantly higher than that in the leaves by realtime quantitative PCR (qPCR), and the CsPAL3 gene was regulated by light. This study provides a scientific basis for further study of the function of CsPAL3 gene in tea tree and the molecular regulation mechanism of tea anthocyanin synthesis and accumulation.