Synthetic biodegradable polyesters such as PBAT suffer from slow biodegradability in ambient conditions. Facing the concern of slow biodegradability, We synthesized polyester in a different route from the conventional synthesis method. Conventional methods made of metal catalysts and chain extenders have increased molecular weight to supplement physical properties. However, there is a trade-off between the molecular weight and biodegradability; increasing molecular weight with urethane linkages deteriorates biodegradability. we envisage a different route: phosphoric acid catalyzed diacid/diol polycondensation to generate polyester chains with phosphate pendant groups (e.g., -O(O)P(OH)2), which were subsequently treated with divalent metal carboxylate (RCO2)2M (M = Zn, Mg, Ca) (Scheme 1b). Phosphate as well as Ca, Mg, Zn ions are essential nutrients in plant growth, the resulting polymers can be a slow-releasing fertilizer during composting. Here, we prepared PBS and derivatives for PBAT prior research. Results were obtained by analyzing tensile property and rheological property. Combing the concepts of macromolecules and aggregates, it was possible to produce polyester having superior mechanical strength and viscosity than conventional polyester. It will also have a positive effect in terms of biodegradability.