Abstract: This paper reported an investigation on the complex effects of liquid/solid organ tin, Ca/Zn composite, rare earth stabilizers and layered double hydroxides (LDHs) as an auxiliary stabilizer on the thermal stability and mechanical properties of soft poly(vinyl chloride) (PVC).Static and dynamic thermal stabilities were characterized by thermal aging test, thermogravimetric analysis and Haake torque rheometer.The results indicated that the use of solid organ tin could lead to a high initial stability and good transparency for soft PVC, whereas the Ca/Zn composite stabilizers made PVC a longterm stability and excellent mechanical properties.Combination of the Ca/Zn composite stabilizers and LDHs can not only improve the thermal stability of PVC, but also enhance its mechanical properties and flame retardancy.