The pipeline leakage monitor system based on Virtual Instrument are introduced in this paper. As an important means of transportation, pipelines have been used all over the world. Pipeline leakage occurs frequently due to pipeline defect, which not only causes great loss of economy, but also leads to serious pollution to the environment. A real-time monitoring system for pipeline leak is established based on virtual instrument. The pipeline leakage detection method is introduced. Several methods of signal processing, including wavelet analysis are utilized to detect and locate pipeline leakage. A pipeline leakage monitor system based on SCADA system is established. The pipeline leakage can be located accurately in time. This system has been applied to about 7,000 Km long distance pipelines in China, which has made great contribution to economy.