The method to decompose sample under dry condition the determination of K, Cu, Zn, Fe、Mn, Cd and Pb in Castanea molissima Blume by atomic absorption spectrophotometer.(FAAS) In this paper, the parameters in FAAS were studied. The elements in Castanea molissima Blume did not interfere whit each other under the given experimental condition.so the authors can examine the seven elements in the same preparation solution. The analytical results of K, Cu, Zn, Fe, Mn were 546.36、8.41、22.38、255.42、161.65μg／ml，Cd and Pb were not found in the samples. The results showed that the recovery of standard addition was 93.9%~103.0%,and the relative standard deviation (n=8) was1.2%~2.2%. The method is simple fast, simple and convenient. The results were satisfactory.