Gui‐ling‐gao (GLG), also known as turtle/tortoise jelly, has been traditionally used as a functional food in southern China, Singapore, and Malaysia to regulate the immune system. In the present study, the antiinflammatory effects of GLG against Concanavalin A (Con A)‐induced inflammation in BALB/c mice isolated splenocytes were evaluated. GLG significantly (p < .05) inhibited Con A‐induced splenocyte proliferation in a concentration‐dependent manner. Con A‐mediated increases in mRNA and protein expressions of inducible nitric oxide synthase (iNOS) and tumor necrosis factor‐alpha (TNF‐α) were suppressed by GLG treatment (p < .001). GLG decreased the upregulated mRNA expressions of interleukin‐1β (IL‐1β) (p < .05) and IL‐15 (p < .001) induced by Con A. These findings suggest that GLG possesses potential antiinflammatory effects by inhibiting the expressions of iNOS and proinflammatory cytokines, such as TNF‐α, IL‐1β, and IL‐15. PRACTICAL APPLICATIONS: The present study revealed that Gui‐ling‐gao (GLG) exhibited potential antiinflammatory effect. Thus, GLG could be employed as an effective health food for regulating immune system to cope with inflammation.