Abstract: <SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">Examined mechanical properties of ethylene-vinyl acetate (EVA) copolymer stuffed by different types of magnesium hydroxide including a general purpose grade,a stearic acid (SA) modified grade and a hexagonal flake.Structures and morphologies of the three types of magnesium hydroxide and EVA/ Mg(OH)</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><SUB>2</SUB> composites were analyzed by FT-IR and SEM.Results showed that the hexagonal and SA modified types of magnesium hydroxide effectively decreased surface polarity while markedly reduced mechanical property loss of the composites compared with the general purpose grade magnesium hydroxide.Dispersion and compatibility of magnesium hydroxide in EVA copolymers were improved by modifying the magnesium hydroxide with 4%(mass fraction) of stearic acid.Such modified magnesium hydroxide yielded a maximal effect on the tensile strength of the composites,while same effect being minimal for hexagonal magnesium hydroxide.The elongation at break reduced below 100% and the mechanical properties of composites deteriorated rapidly when the stuffing of magnesium hydroxide reaches 60 phr(per hundred rubber).</SPAN>