The seeds of Cuscuta chinensis, Cuscutae Semen, are commonly used as a medicinal material for treating the aching and weakness of the loins and knees, tonifying the defects of the liver and the kidney, and treating the diarrhea due to hypofunction of the kidney and the spleen. Since aching and inflammation are highly correlated with such diseases, the aim of this study is to investigate the possible antinociceptive and anti-inflammatory mechanisms of the seeds of C. chinensis. The antinociceptive effect of the seeds of C. chinensis was evaluated via the acetic acid-induced writhing response and formalin-induced paw licking methods. The anti-inflammatory effect was evaluated via the λ-carrageenan induced mouse paw edema method. The results found that 100 and 500 mg/kg of the methanol extract of the seeds of C. chinensis( CC MeOH ) significantly decreased (p < 0.01 and p < 0.001, respectively) the writhing response in the acetic acid assay. Additionally, 20-500 mg/kg of CC MeOH significantly decreased licking time at the early (20 and 100 mg/kg, p < 0.001) and late phases (100 mg/kg, p < 0.01; 500 mg/kg, p < 0.001) of the formalin test, respectively. Furthermore, CC MeOH (100 and 500 mg/kg) significantly decreased (p < 0.01 and p < 0.001, respectively) edema paw volume four hours after λ-carrageenan had been injected. The results in the following study also revealed that the anti-inflammatory mechanism of CC MeOH may be due to declined levels of NO and MDA in the edema paw by increasing the activities of SOD, GPx and GRd in the liver. In addition, CC MeOH also decreased IL-1β, IL-6, NF-κB, TNF-α, and COX-2 levels. This is the first study to demonstrate the possible mechanisms for the antinociceptive and anti-inflammatory effects of CC MeOH in vivo. Thus, it provides evidence for the treatment of Cuscutae Semen in inflammatory diseases.