The Trans Mountain pipeline has characteristics or properties of Natural Monopoly, so it falls into the products of natural monopoly. When there is an economic of scale, that is, average cost decreases as quantity increases, the natual monopoly occurs. As a result, one firm is able to supply total amount of the products at a lower cost in the market than two or more firms. If the govenment does not regulate the Natural Monopoly, it may not benefit the social welfare and the optimal outcomes. In other words, they will produce much less and charge a higher price than social optiaml lead to a high price,low average costs and high profits. Therefore, there are three methods for regulation of the natural monopoly products. First, when market price