The present invention relates to a cosmetic composition comprising:a) at least one polysiloxane bearing a joining group, corresponding to one of the following formulae (IIa) and (IIb):in which:the R radicals represent a C1-C20 hydrocarbon-based group；the Q1, Q2 and Q3 radicals represent either an R radical as defined above；or a joining group capable of forming at least 3 H bonds；it being understood that at least one of the Q1 to Q3 radicals is other than R in formula (IIa)；the Q4 divalent radical represents a joining group capable of forming at least 3 H bonds；b) a polyalkene-based supramolecular polymer which can be obtained by reaction of a functionalised polyalkene polymer with a functionalised joining group, said joining group being capable of forming at least 3 H (hydrogen) bonds.The invention also relates to a cosmetic treatment process using said composition.
