Abstract:The determinated method of Cation Eexchange Capacity in acidic and neutral soil by ammonium acetate centrifugation is classical. However, the disadvantage of this method is complicated distillation process, a long time, and low efficiency. In this paper, the value of CEC in soil was measured by Nessler"s spectrophotometry, and the results were compared with several commonly used traditional methods. Through the determination of CEC values of national standard samples and actual soil samples, the precision of Nessler"s spectrophotometry method is between 2-4%, and the accuracy is consistent with the classical method. Compared with the calssical method, the Nessler"s spectrophotometry method’s distillation step was canceled, determination is simple, interference are less and result is reliable.