Aims: A randomized, open-label, two-period, two-sequence crossover study was carried out for evaluating the bioequivalence of test (T) and reference (R) formulation of gefitinib in healthy Chinese volunteers. Methods: A total of eighty subjects were enrolled and randomized into two sequence groups. All subjects were orally administered of T or R formulation at dose of 250 mg. The plasma samples were obtained at before and after administration until post-dose 168 hour, and the drug concentrations were analyzed using validated high-performance liquid chromatography-tandem mass spectrometry method. Results: The 90% confidence interval of the geometric mean ratios were all within the range of 0.80-1.25 under fasting and fed conditions. As for the safety of both formulations, no serious or unexpected adverse events occurred during the study. Conclusions: Overall, the T formulation was bioequivalent with R formulation under fasting and fed conditions.