The diselenide-containing polycarbonate ((PTMCSe)(2)) and diselenide-containing poly(epsilon-caprolactone) ((PCLSe)(2)) were synthesized by the ring opening polymerization using a new compound of di-(1-hydroxypropyl) diselenide ((HOC3H6Se)(2)) as initiator. The dynamic properties of these diselenide-containing polymers were revealed by a series of diselenide exchange reactions, which could be realized under visible irradiation at room temperature. As the result of the diselenide exchange between (PTMCSe)(2) and (PCLSe)(2), a di-block polymer (PCLSeSePTMC) was formed in (PTMCSe)(2) /(PCLSe)(2) alloy. Taking advantage of the diselenide exchange, the compatibility and miscibility of (PTMCSe)(2)/(PCLSe)(2) alloy was significantly improved by the exchange product (PCLSeSePTMC) which acted as polymeric compatilizer. This novel concept may be applied in other polymer alloys containing dynamic covalent polymers.