Abstract: The paper puts forward a "ton-pipe investment" economic index, introduces the measuring index of pipe cost that covers primary proportion in the investment of pipeline engineering, and compares the tech-no-economic indexes of investment in the pipeline engineering at home and abroad. The paper considers that the index of "ton-pipe investment" converted from the unit investment is more intuitional, relatively accurate, easy to use and calculate the pipe weight for different diameters'pipes used in pipeline construction.