The performances of LDPE/EVA (low density polyethylene/ethylene vinyl acetate copolymer) multiphase polymer blend filled with different amount of nano-aluminum trihydrate (CG-ATH) was investigated in this paper.The mass amount of CG-ATH filled into LDPE/EVA composites ranged from 10% to 70%.Tests results of mechanical properties showed that the elongation at break dropped sharply and the tensile strength dropped at first and went up later. The tensile strength of the composites of CG-ATH/LDPE/EVA reached 12.5 MPa when the amount of CG-ATH got to 60%. Through analysis of SEM photos

the consistent property between CG-ATH and LDPE/EVA multiphase polymer blend can be seen. Results also showed that although CG-ATH was not consistent to the blend

nanoparticles added could strengthen the blend.Tests of flame retardancy and analysis of TG and DSC showed that the addition of CG-ATH increased decomposition temperature of the composite

from 221.6 ℃ to 267.8 ℃.At the same time coking rate and limiting oxygen index(LOI) increased.Optimum mechanical properties and flame retardancy of the composites could be obtained at the CG-ATH’s amount of 60%.