Regular network polyesters were prepared from trimesic (Y), pyromellitic (X) or mellitic (Y-H) acids and 1,6-hexanediol (6G). Prepolymers prepared by melt-polycondensation were cast from dimethylformamide solution and post-polymerized at 260 degrees C for various times to form a network. The resultant films were transparent, flexible and insoluble in organic solvents. Degrees of reaction estimated from the infra-red absorbance of ester and methylene groups were 95, 95 and 96% for 6GY, 6GX and 6GY(H) post-polymerized for 12h, respectively. X-ray diffraction intensity curves showed the formation of some ordered structure owing to the regular networks, and the degrees of ordering were 6GY > 6GX > 6GY(H). Densities were 1.227, 1.290 and 1.289 g cm(-3) and heat distortion temperatures measured by thermomechanical analysis were 75, 72 and 75 degrees C for 6GY, 6GX and 6GY(H) post-polymerized for 12h, respectively. Tensile strengths were in the order 6GY > 6GX > 6GY(H) and Young’s moduli were 6GY(H) = 6GX > 6GY. Dye absorptions were 6GX>6GY>6GY(H), and water absorptions and weight losses in alkali solution were 6GY(H) > 6GX > 6GY. These effects of the number of functional groups on the benzene ring on the structure and properties were discussed, and compared with those of previously reported network polymers.