Recently, we have reported that polyaddition of various diisothiocyanates and dithiols is achieved with triethylamine in DMF at 25 °C for 12 h under nitrogen atmosphere to obtain the corresponding polydithiourethanes (PDTU) in higher yield and molecular weight. Particularly, PDTU containing an aliphatic moiety in the main-chain exhibited excellent optical and mechanical properties compared to that of typical polyurethanes. In this study, aliphatic PDTUs were synthesized from various diisothiocyanates and dithiols having a difference of carbon number, and then the chemical and physical properties of the obtained PDTUs such as solvent solubility, glass transition temperature, thermal stability, transparency, refractive index, and tensile strength, were analyzed in detail by GPC, NMR, IR-ATR, UV-vis, DSC, TGA, tensile testing measurements. Moreover, the cast films obtained from multifunctional isothiocyanate and thiols exhibited excellent chemical and physical properties.