The　magnetic　properties,　structure　defects　of　electrodeposited　Fe-Ni-P　alloys　with　various　compositions　and　the　thermostability　at　amorphous　state　have　been　studied　by　DSC,　positron　annihilation　and　electronic　integrating　instrument　methods.　The　results　show　that　the　thermostability　of　amorphous　Fe-Ni-P　alloys　increases　with　Fe　content.　Emergence　and　recrystallization　of　stable　phases　defer　as　the　P　content　of　the　coating　increases.　The　minimum　H-c,　B-r　and　P-h　occur　at　9.4　P　(wt　pet)　content.　Maximum　H-c,　B-r　and　P-h　occur　at　the　weight　ratio　of　Fe　to　Ni　equaling　to　1/9.