The questions of one-sided waiver are Probed of obligation (contract) in the context of self-defence of civil right and interest. Differentiating of one-sided refuse is conducted in contractual relations, as a mean of guard of legal interest, and law consequences of one-sided refuse, as method of self-defence of the indicated interest. Formulated suggestion about making alteration to Civil Code of Ukraine, rights directed on providing of realization on the self-defence of interest.