Abstract: To obtain Rubisco (Ribulose-1,5-bisphosphate carboxylase/oxygenase) small subunit gene from Sasussured involucrata Kar.et Kir, in this study the gene was cloned and analyzed;Seeking monoclone in established cDNA library randomly for PCR directed with universal M13 primer and sequencing , comparing the sequence in NCBI ,finally we obtained the two rbcs gene homologous sequences ，named Sikrbcs1 and Sikrbcs2. Bioinformatics analysis indicated that the Sikrbcs1 cDNA contained an open reading frame of 540 nucleotides encoding 179 amino acids ,the Sikrbcs2 cDNA contained an open reading frame of 420 nucleotides encoding 139 amino acids. Forecasted the Sikrbcs1 protein relative molecular weight was 20.1042 kD, theoretical PI was 8.9, contained two span membrane structures, the Sikrbcs2 protein relative molecular weight was 15.1093 kD, theoretical PI was7.58, no span membrane structure. Multiple sequence alignment of rbcs proteins revealed that the amino acid sequence of Sikrbcs1 protein showed high identity of 83.89% to those of rbcs from Flaveriapringlei and Helianthusannuus, Sikrbcs2 showed high identity of 57.54% to that of rbcs from Helianthusannuus. Phylogenetic analysis further showed that the Sikrbcs1 and Sikrbcs2 had nearest relationship with Chrysanthemum xmorifolium.