| A field experiment was conducted to determine the effect of different phosphorus rates (P2O5: 0, 75, 150 kg·hm-2 and 225 kg·hm-2) on grain yield components, gain filling, growth rate, phosphorus uptake rate, oil yield and phosphorus use efficiency. The results indicated no significant effect with respect to number of capsules per plant and number of seeds per capsule, while 1000-seed weight, seed weight per plant and seed filling period were obviously increased by 10.09%, 23.01% and 7.62%, respectively. And biomass growth rate, economic growth rate and seed growth rate, P uptake rate, economic P uptake rate, and seed P uptake rate were also increased by 31.40%,37.84% and 29.57%, respectively. Phosphorus use efficiency was reduced by increased phosphorus fertilization, in spite of increase in seed yield (16.97%) and oil yield (17.93%). Seed yield has significantly positive correlation with economic growth rate, seed phosphorus fertilizer weight per plant, 1000-seed weight, seed filling period, biomass growth rate, seed growth rate. For obtaining high production and efficient phosphorus fertilizer utilization in oilseed flax, optimal phosphorus application should be 75～150 kg·hm-2(P2O5) in Lanzhou experimental area. |