The level and form of nitrogen fertilizer could significantly influence the growth and development of plant.The present paper studied the content of chlorophyll by the instrument SPAD-502 after treated with different nitrogen fertilizer level and different nitrogen fertilizer form.The results showed that the contents of chlorophyll in the last expanding leaf of maize seedling treated by levels of 0,100 and 200 kgN·hm-2 respectively had no significant difference,with the value of SPAD ranging from 43.3 to 43.7,but when the nitrogen fertilizer level got to 400 kgN·hm-2,the content of chlorophyll in the last expanding leaf of maize seedling increased significantly,which can be caused by other components in the nitrogen fertilizer,which needs to be further studied.The experiments of nitrogen form showed that maize seedling treated by ammonia nitrogen ((NH4)2SO4) contained more chlorophyll than that treated by saltpeter nitrogen (Ca(NO3)2),and the statistical analysis was significant.The reason for the effect of nitrogen form on the content of chlorophyll of maize seedling leaf could be:(1) it is easier for plants to absorb ammonia nitrogen ((NH4)2SO4) than saltpeter nitrogen (Ca(NO3)2);(2) ammonia nitrogen ((NH4)2SO4) contains more trace elements which can promote the growth and development of plants.