目的：探讨流率延迟对膀胱出口梗阻（ＢＯＯ）分级的影响。方法：对３９例患者取不同起点，以直线被动尿道阻力关系线（Ｌｉｎ－ＰＵＲＲ）行ＢＯＯ分级对比研究。结果：以开放压和关闭压为起点测得的ＢＯＯ分级与Ｐ－Ｑ图显示的ＢＯＯ分级差异有显著性，以ＰｄｅｔＶＢ为起点 Objective: To investigate the effect of flow rate delay on the classification of bladder outlet obstruction (BOO). Methods: Thirty-nine patients were treated with different starting points. The BOO grade was compared with the linear passive urethral resistance line (Lin-PURR). Results: There was a significant difference in BOO grade between BOO grade and P-Q grade as measured by open pressure and closing pressure, and PdetVB as a starting point