Abstract: Improved shaking culture test was applied to analyze the primary biodegradation of Dodecylamine（DA）and Octadecylamine（OA）.According to visible spectra scanning，maximum wave length of DA and OA was 412 nm.In the improved shaking culture test，concentration of OA was determined by heating，adding concentrated hydrochloric acid，and re-dissolving method.According to shaking culture test，primary biodegradability of DA and OA was 99.0% and 97.9%.Results showed that under condition of shaking culture test，DA and OA were both easily biodegradable，and primary biodegradation of DA was easier than OA.In the same conditions，microorganism was augmented making biodegradability of OA improved effectively.The primary biodegradation law of DA and OA could be applied as theoretical basis for treatment of mine wastewater containing primary amine collectors.