Abstract: A decreased silique pedicel angle mutant was obtained by the T-DNA insertion method in Arabidopsis (Arabidopsis thaliana). The mutant SPA gene was cloned using the TAIL-PCR method, and the insertion site was verified by the PCR and RT-PCR. After transformed with the SPA gene, the silique angle of the spa mutant can be rescued to the size of the wild type plants. These results suggest that SPA may play important roles in regulating plant silique angle.