Through selecting zircon sand as raw materials of sand

yttrium oxide（Y

2

O

3

）and phenolic resin as filler and binder

coated zircon sand was prepared by thermal method

and zirconium sand mold was prepared by selective laser sintering（SLS）to pour pure titanium castings by rapid prototyping process.The interfacial reaction between titanium alloy and mould was analyzed.The results show that the titanium castings with clear profile and clean surface and interface reaction layer only about 3μm can be fabricated successfully by SLS coated zircon sand casting with Y

2

O

3

coating.Oxidation products in casting surface are composed of TinO

2n-1

and TiO

2

.The thickness of O diffusion enrichment solution layer is about 1μm

which is TiO

2

.