Abstract: Using the L₁₆(4⁵) orthogonal experimental design, factors including ashing temperature , ashing time ,atomization temperature, atomization time were studied in the determination of cadmium in rice by graphite furnace atomic absorption spectrometry. The instrument parameters were determined : the optimized ashing temperature, ashing time, atomization temperature, and atomization time were 450 ℃, 15 s, 1 750 ℃ and 4 s, respectively.