Abstract: In order to study the effects of autumn fertilization on the growth and flowering of Pinus koraiensis grafted seedlings with different rootstock types, three kinds of Korean pine grafted seedlings with different rootstock types（Pinus sylvestris var. mongolica, P. koraiensis, P. armandii） were selected as the research objects. Four autumn nitrogen application levels（0, 0.5, 1.0, 1.5g/plant） were set up to determine and analyze the growth, physiology and flowering response of three kinds of Korean pine grafted seedlings to autumn fertilization. The results showed that: nitrogen application in autumn could significantly increase the accumulation of chlorophyll, nitrogen and soluble protein in the scion at the end of the growing season of Korean pine grafted seedlings, promote the growth of the scion in the next growing season, and increase the flowering plant rate and total flowering number. Different types of rootstock grafted seedlings had different responses to autumn fertilization. When the rootstock type was P. sylvestris var. mongolica and P. koraiensis, the optimal autumn nitrogen application rate was at a medium nitrogen level（1.0 g/plant）. When the rootstock type was P. armandii, the optimal autumn nitrogen application rate was at a high nitrogen level（1.5 g/plant）. Under the same medium nitrogen treatment conditions, autumn fertilization had a more significant promoting effect on the flowering ability of the scions of P. sylvestris var. mongolica grafted with P. koraiensis seedlings in the following year, and a more significant promoting effect on the growth of the scions of P. koraiensis grafted with P. koraiensis seedlings in the following year. The phenomenon of overwintering death occurred in P. armandii grafted with P. koraiens seedlings, and autumn fertilization could reduce the overwintering death rate of seedlings by 34.45%.