Abstract: On the basis of the hydraulic transient equations of all kinds of pipelines boundaries and the interlocked Allievi equations, the analysis schedules and computation programs for liquid transients in long pipeline with real elements and boundaries based on the finite differential solution of MOC (method of char-acteristics) have been designed in this paper.So the hydraulic simulation of fluid transients has been carried out successfully.After the results of pipeline nodes have been interpolated in accordance with B-spline interpolating function, the pressure profile and the variation curves of other hydraulic parameter can be drawn on the computer screen and output to the printer.