Abstract:Selected green vegetables， cabbage， spinach， Chinese cabbage four representative leafy vegetables， using a simple visible spectrophotometry was studied nitrite content before vegetables were fried and after， the nitrite content of leafy vegetables change trends at room temperature and low temperature. The results showed that： the nitrite content of green vegetables， cabbage and Chinese cabbage when just Fried fry than before has been reduced. The nitrate content of green vegetable， cabbage acsended at room temperature in the 12 hours， spinach and Chinese cabbage appeared nitrification peak at the twelfth hour， after sixteenth hours decreased. The nitrite content slow growth under the low temperature （4 ℃） storage.