[Problem]To provide a screening method for a substance having an anti-obesity action and an anti-obesity drug.[Solution]A screening method including: a step for contacting a test substance and a synoviolin-gene-expressing cell and a step for verifying the effect of the test substance on the synoviolin gene expression, or the effect thereof on synoviolin protein activity. An action which reduces the amount of adipose tissue and an action which inhibits induction of adipocyte differentiation are examples of an anti-obesity action. An anti-obesity drug containing, as an active ingredient thereof, an siRNA of synoviolin, a decoy nucleic acid of synoviolin, or an antisense nucleic acid of synoviolin.
