This paper studies thermoeconomic synthesis design of heat piping.An optimal the rmoeconomic synthesis method of designing heat piping is presented.Using this me thod makes the designed piping have the characteristics of the synthetic minimum of energy loss construction and mainteuance costs,and excellent technical quali ty.It shows that the application of the method to a steam piping design can achi eve saving of operating cost by about 20 percent against the design made by non- thermoeconomic synthesis method.This method can be applied to other piping as well.