The fibroblast in the periodontal ligaments received various stress. Among them, compression and tension are quite important and they are related to the remodeling of tooth and alveolar bone. We studied the change of expression of interleukin-6 (IL-6) and interleukin-8 (IL-8) in the fibroblasts of the periodontal ligaments by real-time RT-PCR and ELISA. In results, the relative activity of IL-6 mRNA in 2 hours after was 1.54${pm}$0.08 and 1.00${pm}$0.05 in control and test, respectively (P<0.05). Its 12 hours after was 1.23${pm}$0.06 and 2.78${pm}$0.14 in control and test, respectively (P<0.05). The relative activity of IL-8 mRNA in 2 hours after was 1.00${pm}$0.05 and 0.24${pm}$0.01 in control and test, respectively (P<0.05). Its 12 hours after was 1.23${pm}$0.06 and 0.63${pm}$0.03 in control and test, respectively (P<0.05). The concentration of IL-6 was 1.02${pm}$0.16 ng/ml, 0.90${pm}$0.14 ng/ml, and 1.32${pm}$0.12 ng/ml (P<0.05) in control, 2, and 12 hours after, respectively. The concentration of IL-8 was 2.26${pm}$0.17 ng/ml, 1.70${pm}$0.26 ng/ml (P<0.05), and 0.84${pm}$0.47 ng/ml (P<0.05) in control, 2, and 12 hours after, respectively. In conclusion, the expression of IL-6 was significantly increased after the application of the static compressive force, but IL-8 was significantly decreased. Considering their known function, their expression is quite important in tooth and bone resorption.