对用气相色谱法测定稻米中毒死蜱农药残留的不确定度进行了评定。通过对测定过程中各变量的分析，确定了不确定度的来源，建立了相关数学模型，并对各变量的不确定度进行计算，最终算出合成不确定度。当水稻中的毒死蜱农药残留量为0.107 mg/kg时，测定结果的扩展不确定度为0.013 mg/kg（k=2）。

The uncertainty of determination of chlorpyrifos residue in rice by gas chromatography was evaluated in this paper. By analyzing the various variable parameters among the procedures, the components of uncertainty were identified, the mathematical model was established, and every components of uncertainty was calculated, thereby, the combined uncertainty was finally obtained． The expanded uncertainty was 0.013 mg/kg（k=2） with 0.107 mg/kg of the content of chlorpyrifos residue in rice.