Abstract: The whole pigging process for a newly-built small diameter gas pipeline of some gas processing plant is introduced. In allusion of the "miss" of several pigs during the pigging operation, the site analysis on the problem is made. According to analysis result, some improvement measures such as pigging operation according to the work procedure, setting up the monitoring point of pig along the pipeline on a basis of rationa way and information transfer in the whole line are considered to be taken.