The canopy spectral reflectance and chlorophyll content of corn weremeasured and analyzed under different nitrogen treatments. The trends ofchlorophyll content were discussed based on different growth stages and differentnitrogen levels. It was observed that the chlorophyll content increased with theincrease in nitrogen, and could be affected by the environment changes includingthe temperature, rain, fertilizer treatment and so on. The characteristics ofcanopy spectral reflectance indicated that the canopy spectral reflectancechanged significantly at different stages. In the visible region (400-750 nm),the reflectance increased and reached the maximum until the shooting stage, anddecreased subsequently with the growth progress. In near-infrared region (750-1000 nm), the spectral reflectance climbed sharply. It increased from tilleringstage to shooting stage first, and then began to decline at trumpet stage and wasraised again at anthesis-silking stage. At milking stage, the reflectance wasdecreased again. There were clear distinctions of visible reflectance indifferent nitrogen regions. At shooting stage, with the increase in nitrogen thereflectance decreased at chlorophyll absorption band (430-450 nm, 640-660nm).Investigating the reflectance of the corn canopy under the different nitrogentreatment, it was found that the reflectance was higher in normal fertilizingregion than others in 550 nm, with RNormal>RLow>RHigh. At trumpet stage, thecanopy reflectance in low fertilizing region was higher than others in thevisible region. It was clear that the corn canopy reflectance of normalfertilizing region was the same as high fertilizing region. The results indicatedover fertilizing could not help increase the corn nitrogen uptake. The studyprovided the basic information of chlorophyll measurement based on spectraltechnology and could help to guide the precision fertilizer in the field.