The forming-regions and properties were studied on phosphate system glasses Sm2O3 doped by two step melting method. It shows that with the increasing of rare earth content, the forming-regions would shrink and the content of Sm2O3 should be controlled in 15 mol %. The structure and absorption spectrum were tested by infra-red spectrum and spectrophotometer. The experimental results provide that with the. increasing of Sm2O3 content, the characteristic absorption peak of 1280 cm- 1 would move to the low wave numbers and vibration weakening, in the absorption spectrum,the intensity of characteristic absorption peak was enhanced and broadened at 1075 nm, and the transmittance of 1060 nm is lessthan 1% .