The present invention pertains to a co-modified organopolysiloxane having a group having a siloxane dendron structure and a group containing a saccharide component (ideally, a sugar lactone amide alkyl group), a production method therefor and a surface treatment agent, a powder treatment agent, a powder-in-oil dispersion, and an externally used drug composition, etc. that comprise the obtained co-modified organopolysiloxane.
