Abstract: The economic forecasting, one of the modern managerial methods, is getting more and more attention and bas come to be an independant science. The article, by explaining the practical application of the principles of forecasting in cross-country oil pipelining enterrpises, makes an exploring study of the general steps, methods and some notices in application of forecasting. It puts forward the ideas of basic index and the suggestion as to set up the schematic diagram to predict the economic index relationship, which is of instructive significance to the determination of forecasting steps and organizations. It further points out the necessity to stand higher in analysing the long-term inclination of the economic index fluctuation, macroscopically linking the self-variable factors. In selection of the prediction model parameters, it is necessary to generalize the developing trend of the object itself, in addition to making comparison of the various errors, so as to select the parameters closely in conformity with the developing trend.