Abstract: [Objective]Quantitative Analysis of color plays major role in inheritance and breeding of naturally colored cotton. [Method]In present study,pigment of color cotton fibers was extracted and the absorbance was measured using scanning UV spectrum. [Result]It is observed the absorbance peak of the green color fiber pigment extraction solution occurred at 252 nm,and the absorbance peak moved heading to direction of shortwave gradually with decreasing the concentration of green color pigment,while the absorbance peak of brown color fiber pigment extraction solution moved more obvious heading to the direction of ultraviolet region shortwave,compared with green color pigment. The quantitative relationship between absorbance and the concentration of different color fibers pigment was calculated and the highest correlation coefficient was screened from all absorbance values (200-700 nm),it is concluded that 417 nm and 613 nm were considered as characteristic wavelength for green color fiber and brown color fiber respectively. The regression equation between pigment concentration and absorbance were Cgreen=0.053 5 A (R~2=0.996 5) for green color fiber and Cbrown=0.021 7 A (R~2=0.987 8) for brown color fiber respectively. From this study a conclusion can be drawn that scanning UV spectrum method is a very powerful tool to determine the pigment content of color fiber. [Conclusion]Therefore,this method has very important significance for colored cotton breed.