Abstract: According to requirements of pattern materials and shells in near netshape investment casting production,The paper studies high properties Pattern materials on the basis of olefin and the composite mould shell of colloidal silica sodium silicate binder.The results show that the M6 pattern material meeets technical requirement,The properties are as followsdropping point is 59.2℃;linear contract percentage is 0.88%;bending strength is 6.10MPa;thermal stability is 1.44 mm(34℃,2h).These performances are better than those of pattern material comprised of paraffin and stearic acid which is popular in foundry work.Castings of composite mould shells using sodium silicate sodium silicate binder is better than that of mould shells using single binder sodium slilcate binder in dimensional accuracy and surface quality.