A series of polyesteramides with randomly introduced ester/amide group ratio of 50/50 were newly synthesized by reacting terephthaloyl chloride, isophthaloyl chloride and sebacoyl chloride with tyramine and tyrosine. The polymerization was carried out by interfacial polymerization in two phase solvent systems, which gave various polyesteramides with moderate molecular weights in good yields. The chemical structures of the polymers were confirmed by $^1$H NMR, IR and elemental analysis. Tyrosine based polyesteramide was degraded thermally around 29$0^{circ}C$ to give the polyesteramide, which was obtainable from tyramine. Thermal stability and degradation behaviors were examined by differential scanning calorimetry and thermogravimetric analyses.