Objective: To investigate the effect of temporomandibular joint (TMJ) disc perforation on expression of type Ⅰ collagen in TMJ disc cells. Methods: The fibroblastic-like cells from the surgical removed TMJ disc tissue (disc perforation or TMJ condyle hyperplasia) were cultured. The cultured cells were identified as fibroblastic-like cells by toluidine blue and immunofluorescence staining. The expression of type Ⅰ collagen was detected with Western blotting and the content of type Ⅰ collagen was examined by enzyme linked immunosorbent assay (ELISA). Results: Fibroblastic-like cells were cultured from TMJ disc cells and the controls. The collagen-Ⅰ and collagen-Ⅱ were positive in both toluidine blue and immunofluorescence staining. In Western blotting, the expression of typeⅠcollagen in cells from joints with disc perforation was lower than that from normal joints. The content of collagen-Ⅰ was (1.62±0.52) μg/L from controls, and (0.85±0.33) μg/L from disc perforation respectively (P=0.0134). Conclusions: The disc cells from TMJ with disc perforation expressed lower type Ⅰ collagen than that from controls, which may be related to the lower content of collagen-Ⅰ in TMJ disc and the formation of TMJ disc perforation.