Abstract: A series of poly(butylene succinate co 1,2 hexylene succinate)（PBSH） and poly(butylene succinate)（PBS） were synthesized by direct esterification and polycondensation of succinic acid with 1,4 butanediol and 1,2 hexanediol. The molecular weight, chemical structure, thermo property, rheology of PBS and PBSH were characterized with Ubbelohde viscometer, 1H NMR， DSC and rheometer, respectively. The results show that with increasing the amount of 1,2 hexanediol the melting temperature(Tm), crystallization temperature(Tc), the degree of crystallinity(Xc), tensile strength and flexural strength decrease, while the elongation at break increases significantly. The introduction of 1,2 hexanediol has a certain impact on the zero shear viscosity(η0), storage modulus(G′), and loss modulus(G″) of PBS.