Objective To observe and approach the correlation of suffering liquid reflow in epidural space and the anesthesia effect, According the character of liquid reflow, decides whether to inject local anesthesia drug, which could avoid the toxic reflection. Methods selective epidural anesthesia 2000 patients ( ASAⅠ～Ⅲ, age, sex, weight , which were not limited )were enrolled. All patients were on left recumbent position, and were punctured by normal beam testing. no bubble compress,which affirmed to enter into epidural space. Insert the epidural tube to 20cm, then draw back the puncture, detain the epidural tube 3cm in epidural space. Draw 3ml saline with syringe, and connected it into the end of the tube. Observed whether there was liquid reflow: yes(1), no(2). Meantime observe the character of reflow liquid 5minutes (-clear, +week red, ++obviously red, +++deep red, ++++ redness) .If the character was beyond (++), injected the different concentration normal dose to complete the surgery. Continously observe the characters of liquid reflow, anesthesia effect and complications. Results The suffering reflow liquid has correlation with anesthesia effect. One patient’s reflow liquid was found blood, stopped injecting the drug into epidural space, and avoided the toxic reflection. All patients had no nerve or spinal cord complications. One patient’s reflow liquid was blood post operation. Conclusion Epidural liquid reflow, which can be epidural anesthesia success index, effectively avoid toxic reflection, monitor and cope with the epidural hematoma immediately.