Abstract: Leukotriene B₄ (LTB₄),one of the metabolites of arachidonic acid via5-lipoxygenase (5-LO),plays important role in some inflammatory diseases as one of the most potentchemotaxis factor. A radio-ligand binding assay was set up and the characteristics of LTB₄ receptor onguineapig splenocytes membrane were studied.At 25℃,the Kd was found to be 1.55 × 100-9mol·L^-1 and the B_max was 2.59×10-13 mol·mg^-1 protein. The assay established was evaluated bynordihydroguaiaretic acid (NDGA) as positive control.