〔Abstract〕 Objective To investigate the effect of secreted protein, acidic and rich in cysteine(Sparc) on the proliferation and apoptosis of human keloid fibroblasts(HKF) and normal fibroblasts(NFs), as well as the expression of collagen type Ⅰ and collagen type Ⅲ in the extracellular matrix. Methods HKF and NFs were isolated and cultured. The two types of cells were both divided into experimental group and control group in which the experimental group was incubated with Sparc while the control group was incubated with the same amount of DMEM. CCK-8 experiment was used to test the influence of Sparc on each cell proliferation; flow cytometry was used to test the influence of Sparc on each cell apoptosis; Western blot and RT-PCR were used to detect the expression of collagen type Ⅰ and collagen type Ⅲ on each group. Results SPARC could significantly promote the proliferation and inhibit the apoptosis of cells in each group, and SPARC could obviously promote the expression of collagen type I and Collagen type Ⅲ in each group. Conclusion SPARC is an important protein to promote the formation of keloids, which can be targeted to regulate the formation of keloids.