Abstract: Hyperbranched ethylene-diamine triazine polymer(HBP) was first prepared through a one-step synthetic method by using ethylenediamine and cyanuric chloride as raw materials, and then poly(propylene carbonate)(PPC) was modified with HBP through a melt blending method. The resulting compounds were characterized by differential scanning calorimetry, thermogravimetric analysis, tensile and impact measurements, rotational rheological test and scanning electronic microscopy. The results indicated that the modified PPC achieved an improvement in tensile strength by 50 % and in elongation at break by 55.4 % when 1.5 wt % of HBP was incorporated. The glass transition temperature and decomposition temperature of the modified PPC also increased in the precence of HBP. HBP was considered as an effective modifier for PPC.