Abstract: WRKY transcription factors play critical roles in plant development and stress responses. To elucidate the biological function of the WRKY transcription factor in rubber tree (Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg.), bioinformatics methods were used to conduct phylogenetic analysis of HbWRKY12a. The gene fragment of HbWRKY12a was amplified and cloned via RT-PCR. HbWRKY12a was heterologously overexpressed in Arabidopsis thaliana, and its effects on flowering time and salt stress responses were examined. The results showed that compared with wild-type plants, HbWRKY12a overexpression lines exhibited significantly earlier flowering under both long-day and short-day conditions. Moreover, HbWRKY12a overexpression resulted in a marked reduction in salt tolerance under salt stress. These findings indicate that HbWRKY12a functions as a regulator of flowering time and salt stress responses in plants.