Based on data of NPK and output value of crops in Beijing,Tianjin and Hebei province from 1990 to 2013,this paper constructs the VAR model and uses the impulse response and variance decomposition methods to explore the correlation between the use of NPK and the output value of crop.There is a long-term of equilibrium relationship between the use of NPK and output value of crop; NPK shocks a little wave amplitude to output value of crop.But the impact duration is different.The impact on Beijing has the longer duration compared to Tianjin and Hebei province.In general,the contribution rate of the three kinds of fertilizer elements on the output value of crop in Beijing,Tianjin and Hebei province is low.The order of contribution rate of fertilizer component sorted in Beijing is P>N>K,while it is K>N>P in Tianjin and Hebei province.