The　waveguided　metallic　photonic　crystal　biosensor　based　on　gold-silver　alloy　material　is　expected　to　achieve　better　sensing　sensitivity　than　the　same　structure　of　pure　gold.　By　using　the　gold-silver　alloy　nanoparticles　as　＂building　block＂,　we　successfully　assemble　one-dimensional　waveguided　metallic　photonic　crystals　through　a　solution　processible　method.　This　is　a　simple　and　low　cost　method　to　fabricate　one　or　two　dimensional　metallic　crystals　in　large　area.　The　sensitivity　of　the　biosensor　based　on　the　gold-silver　alloy　waveguided　metallic　photonic　crystal　is　2.5　times　that　of　the　same　structure　made　by　pure　gold.　The　gold-silver　alloy　nanoparticles　assembled　waveguided　metallic　photonic　crystals　exhibits　potential　application　in　biosensing　due　to　its　low-cost　and　simple　testing　methods.