An object of the present invention is to provide a lubricant having excellent lubrication performance. Further, another object of the present invention is to produce a polyester composition having a small load on an environment and mass productivity. The present invention relates to a production method for a complex polyester composition including a step of obtaining a complex polyester composition by condensing polyhydric alcohol, polycarboxylic acid having at least two carboxyl groups and carbon atoms of greater than or equal to 5, monohydric alcohol having at least one oxyalkylene group in the absence of a solvent, in which a component having a weight average molecular weight of less than or equal to 1300 in a GPC chart of the complex polyester composition is less than or equal to 43 area%. Further, the present invention relates to a complex polyester composition, a lubricant composition, and a lubricant.