Abstract: The invention relates to an injectable composition intended for tissue induction of the soft tissues by a system of immediate and prolonged progressive release. In particular, the invention relates to a composition comprising a gel of at least one first biodegradable polymer forming a first agent for filling soft tissues in an animal, and a suspension in this gel of microspheres with an average diameter between 5 and 50 micrometres, said microspheres comprising 50 to 90 wt. % of at least one biodegradable polysaccharide relative to the total weight of the microspheres, said microspheres inducing a second filling by tissue induction and containing at least one second biodegradable polymer forming at least one third filling of the soft tissues in an animal.