Cotton production for accurate non-destructive, rapid monitoring of plant nitrogen content there is an urgent demand. Canopy spectral characteristics of the cotton plant and its quantitative relationship between nitrogen content, can achieve non-destructive monitoring of cotton nitrogen. Two consecutive years by different nitrogen test, cotton canopy hyperspectral data collection and simultaneous determination of canopy nitrogen content, analysis of different fertilizer treatments of cotton canopy spectral characteristics and the relationship between nitrogen content of cotton, the results show that: nitrogen content of cotton plant in different periods and spectral reflectance in the visible band (400～700 nm) was negatively related to the near-infrared 700～1 300 nm band was a significant positive correlation, and in the short-wave infrared 1 300～1 800 nm band correlation is more complicated. Canopy scale, the whole growth stage of cotton, the visible band are sensitive to nitrogen content in cotton band, and near-infrared only is the cotton boll nitrogen content of the sensitive band; short-wave infrared band only in the budding period Cotton nitrogen sensitive band. Using nitrogen-sensitive bands in different periods can be constructed Cotton Cotton Nitrogen monitoring indicators.