Abstract: Abstract: Objective To investigate the expression of CytC in the labial glands of patients with primary Sjogren’s syndrome (pSS) and explore the effects of CytC on pSS. Methods Immunohistochemistry and RT-PCR were used separately to examine CytC protein and mRNA in labial glands in 40 patients with pSS and 22 patients with non- pSS and to make an analysis of their differences. SPSS12.0 software package was used for t test. Results The expression levels of CytC protein and CytCmRNA in 40 patients with pSS were higher than those in 22 patients with non-pSS. (P<0.05). There was significant difference between pSS and non- pSS. Conclusion The study reveals that the CytC expresses abnormally in the labial glands of patients with pSS.