Abstract: A SIZ1-like gene was firstly cloned from Dendrobium cDNA library and named as DenSIZ1. Using the bioinformatics software, the physical and chemical properties, composition,secondary structure, tertiary structure, subcellular localization and functional structure domain were analysized and predicted. The results showed that DenSIZ1 probably belongs to PIAS family member of SUMO E3 ligase and includes three important function domains of SAP, PHD and zf-MIZ. Moreover, it is located in cellular nucleus and have higher homology with PIAS family