15N micro-plot experiment was conducted in Yixing city of Taihu Lake area to study characteristics of soil and fertilizer N uptake in Wuyunjing 23 (W23), Zhendao 11 (Z11) and Wuyujing 3 (W3) before and after rice heading stage, N residue in soil and environmental N losses. W23 and Z11 were cultivated recently and planted widely as high-grain rice varieties, while W3 was earlier bred with relatively lower yield. The results showed that W23 and Z11 accumulated obviously greater total N, soil N and fertilizer N than W3 did during whole growth stage. There was no difference in accumulations of 3 kinds of N for these rice cultivars before heading stage. W23 and Z11 had stronger ability in absorbing soil and fertilizer N than W3 after heading stage, especially for fertilizer N. The uptake of N from soil by W23 and Z11 was increased by 89.3%–134% and by 119%–157% from fertilizer compared with W3. Increase in N application rate enhanced uptake of N from soil by W23 and Z11 before heading stage, but did not affected N uptake from soil and fertilizer after heading stage. There were no significant differences in soil N residues of fertilizer N detected by15N trace method, total N, alkali-hydrolyzable N, NH4+-N and NO3–-N in cultivated soil among various rice varieties at N200 and N270 levels. W23 and Z11 were environment-friendly rice cultivars under the same N application rate due to less N losses into environment compared with W3.%在太湖地区宜兴市采用15N 微区示踪试验，研究了太湖地区推广种植高产水稻武运粳23号(W23)和镇稻11号(Z11)及育种较早相对低产品种武育粳3号(W3)在不同供氮水平下齐穗期前后对土壤氮和肥料氮的吸收累积特性，土壤氮残留及其环境效应。结果表明：W23和Z11在N200(N，200 kg/hm2)和N270(N，270 kg/hm2)水平下整个生育期吸收累积3种类型氮量(总氮、土壤氮和肥料氮)均显著高于 W3。不同水稻品种齐穗期前吸收累积3种类型氮量无显著差异，W23和Z11齐穗期之后对土壤氮和肥料氮的吸收能力均明显强于W3，特别是肥料氮，分别比W3高89.3%~134%和119%~157%；施氮量增加促进了W23和Z11齐穗期前对土壤氮的吸收，但对不同水稻品种齐穗期后对土壤氮和肥料氮的吸收无明显影响；不同水稻品种在两种供氮条件下的稻田土壤肥料氮残留(15N示踪)，全氮、碱解氮、NH4+-N 和 NO3–-N 均无明显差异；在同等施氮条件下，高产品种 W23和 Z11整个生育期稻田氮向环境的排放量低于W3，是相对环境友好型水稻品种。
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