Abstract: As most parts of China West Products Pipeline are constructed in hilly areas, the elevation will bring problems to the commissioning of West Pipelines. The paper presents an analysis on pipeline water filling process, the influence of equipment and diesel on the contaminant, and the probability and danger for pipeline segment accumulated with gas, which will influence on the commissioning of pipelines in elevation areas. Possible problems for the segments in elevation areas are put forward, and some methods and suggestions which can solve or avoid the problems are proposed in the paper.