Abstract: Local Corrosion occurs in plant piping when oil pipeline and equipment are aging with time. Through sampling investigation, the following positions are recognized where local corrosion is most likely to occur: the bottom of hurried pipes through wall, contacting areas between pipe and its support, the connection between insulated pipe and pressure guage, etc. Local corrosion results from soil corrosion, spot corrosion, crevice corrosion, concentration cell corrosion, micro-cell corrosion, etc. Such measures against the said corrosion are taken as CP system, corrosion inhibitor, correct surrounding medium for pipe, effective corrosion/water proof layer, and internal corrosion prevention.