The　content　of　dopant　Ga3+　ion　in　Ga3+:KTP　crystal　was　measured　by　ICP-AES　method,　and　the　average　distribution　coefficient　in　the　growth　system　of　Ga3+　was　obtained　(0.0373).　The　conductivity　along　c　axis　of　Ga3+　:　KTP　crystal　was　measured　by　electrometer　and　multifrequency　measurer,　and　compared　with　that　of　the　pure　KTP　crystal.　The　result　shows　that　the　conductivity　along　c　axis　of　Ga3+:KTP　crystal　was　decreased　by　more　two　orders　of　magnitude　vs.　that　of　the　pure　KTP.　The　mechanism　is　discussed　in　this　article.