A series of FeAlPO-5 molecular sieves were synthesized by the hydrothermal method with completed and incompleted solubility aluminum source. The catalysts were characterized by X-ray diffraction (XRD), IR and scanning electron microscopy (SEM) and evaluated in the catalytic reduction of N2O with CH4. The results showned that the structure and morphology of FeAlPO-5 were affected by the gel preparation conditions such as aluminum source solubility, iron loading. The aluminum source complete solubility is the primary factor to control the formation of tridymite phase. The excess iron loading also led to the transformation of AlPO-5 from AFI structure to tridymite phase. The Fe species in the FeAlPO-5 with the AFI structure have great effects on the N2O conversion. The 1.8 percent FeAlPO-5x, with coexistence of AFI structure and tridymite phase shows good low temperature activity in the catalytic reduction of N2O with CH4. This can be explained by the formation of the ex-framework Fe(II) species from the crystallization competition of the tridymite phase with the AFI structure.