目的　了解新生鼠输尿管不全梗阻后肾盂压力和肾脏形态的变化。方法　 6 5只新生鼠用腰大肌包埋不同长度的左侧输尿管 ,制成轻 (n =31)、重 (n =34)度输尿管不全梗阻。对照组仅进行剖腹探查。术后 8周和 2 4周分别用核磁共振检查肾脏形态变化 ,术后分别于 2 4周和 30周进行肾盂测压和组织学检查。结果　梗阻肾脏均有不同程度积水。严重梗阻组除积水较严重外 ,发现 4例肾脏肾发育不全 ,其平均肾实质重量仅是对照组的 35 %。轻度梗阻组和对照组未见发育不良的肾脏。严重梗阻组的肾脏灌注压明显高于轻度梗阻组和正常对照组。结论　新生鼠输尿管不全梗阻后均产生明显肾积水。严重梗阻组可产生肾脏发育不良 ,可能与严重梗阻组肾盂灌注压明显增加有关 Objective To investigate the changes of renal pelvic pressure and renal morphology after neovascular ureter obstruction. Methods Sixty-five newborn rats were implanted with left ureter of different length with psoas muscle to make uretero-obstruction with light (n = 31) and severe (n = 34). Control group only laparotomy. Renal morphological changes were examined by nuclear magnetic resonance (MRI) at 8 and 24 weeks postoperatively. Pyretic pyelography and histology were performed at 24 weeks and 30 weeks postoperatively. Results obstructive kidney have varying degrees of water. Severe obstruction group in addition to water more serious, found in 4 cases of renal hypoplasia, the average renal parenchymal weight is only 35% of the control group. Mild obstruction group and control group, no dysplastic kidneys. Renal perfusion pressure in severe obstruction group was significantly higher than that in mild obstruction group and normal control group. Conclusions Neonatal rats have obvious hydronephrosis after obstruction of ureter. Severe obstruction group can produce kidney dysplasia, may be associated with severe obstruction group significantly increased renal pelvic perfusion