To provide a method of detecting abnormal bone metabolismby using a gene strongly expressed in an osteoclast； a methodof screening a compound having a therapeutic and/or preventiveeffect on abnormal bone metabolism； and a pharmaceuticalcomposition for treating and/or preventing abnormal bonemetabolism.[Means for Resolution] Provision of a method of detectingabnormal bone metabolism by using the expression of humanSiglec-15 gene as an index； a pharmaceutical compositioncontaining an antibody which specifically recognizes humanSiglec-15 and has an activity of inhibiting osteoclastformation； and the like.
