Abstract: Nutrient cycling rule in paulownia and crop in-tercropping system,in which paulownia was mainly consid-ered,was studied.TheresultS showed that the contents of nu-trient elernents in different organ;of Paulownia varied with seasons;the annual total uptake of nutrient elerments was 471.96kg/hm²,composed of N 155.14kg/hm².P 80.08kg/hm².K87.04kg/hm².Ca 119.46kg/hm² and Mg 30.23kg/hm², the annual return amount of nutrient elements was 331.62kg/hm²,composed of N 102.57kg/hm², P 43.29kg/hm²,K 63.65kg/hm²,Ca 97.36kg/hm² and Mg 24.74kg/hm². The circulation rate of nutrient elements was 70.26%,com-Dosed of N 66.11%,P 54.06%,K 73.13%,Ca 81.50%and Mg81.81%. 

Key words: Paulownia, Paulownia and crop intercrop-ping, nutrient cycling, circulation rate