The effect of nitrogen supply on absorbing nitrogen feature and yield of "double low" oilseed rape was studied by using of pot experiment.Results indicated that

for supplying nitrogen oilseed rapes

their nitrogen accumulation amounts quickly increased from seedling to later stage of stem enlongation

while declined from later stage of stem enlongation to later flowing stage

increased after flowing stage

which does not still exceeded nitrogen accumulation amounts of later stage of stem enlongation.The same change tendency was found in treatments without nitrogen supply

however

the change intensity was obviously less than those of supplying nitrogen treatments

and nitrogen accumulation amount at later flowing stage exceeded that of later stem enlongation stage.Whether supplying nitrogen or not

nitrogen amounts of nutritive organs continuously decreased with plant growing

reproductive organ nitrogen amounts of plant with supplying nitrogen also continuously decreased

nitrogen amounts of that without supplying nitrogen was shaped in a single peak curve.The time of dry matter accumulation maximum rate of oilseed rape without supplying nitrogen appeared earlier than that with supplying nitrogen

while nitrogen physiological efficiency of oilseed rape with nitrogen supplying was highest at siliquing period

that without nitrogen supplying at later period of flowing.For this reason

nitrogen supplying could obviously increased plant nitrogen accumulation amount

nitrogen content of plant

biomass and seed yield

but decreased nitrogen physiological efficiency.