Abstract: During the pour point depressant (PPD) test in Beisantai-Wushihua Oil Pipeline in Xinjiang, a high point "rebound" was tested. After analysis, it was identified as a "Fanxian Phenomena", that is, the method on needle valve sampling with high pressure caused the sample and pour point distorted. By developing the flow-pressure-releasing sampling method, the above judgment was confirmed and true sample and pour point are obtained. Taking the test result of Caishisha blend oil with 40 ppm PPD for example, the paper demonstrates the implementation process and effectiveness for the flow-pressure-releasing sampling method.