At　present,　the　applications　of　AlxGa1-xN　are　extensive,　such　as　for　visible-blind　ultraviolet　detectors,　laser　diodes,　light　emitting　diodes　(LEDs)　and　HEMTs.　In　this　paper,　Al0.25Ga0.75N　and　Al0.32Ga0.68N　films　have　been　grown　on　2　in　Si　(111)　substrates　by　MOCVD.　The　low-temperature　(6　K)　photoluminescence　(PL)　spectrum　and　XRD　rocking　curve　measurements　have　been　employed　to　study　the　crystal　quality　of　samples,　and　the　phonon　replica　peak　can　be　observed,　which　indicate　that　the　samples　have　better　quality　in　a　small-localized　region.　The　surface　morphology　of　samples　was　investigated　by　AFM　and　the　result　of　wavy　surface　agrees　with　the　deduction　from　XRD　rocking　curve　measurements.　The　sheet　resistance　mappings　have　been　shown,　and　it　indicates　the　nonuniformity　of　A1GaN　film　on　Si　(111)　will　increase　sharply　as　the　Al　content　increases.