A new type of immobilized palladium, PI (polymer incarcerated) Pd (2b), from Pd(PPh(3))(4) and copolymer (1b) has been developed. The excellent activity of PI Pd has been demonstrated in hydrogenation of various olefins, benzyl ethers, and nitro and aromatic compounds. PI Pd is tolerant under high pressure and high temperature and can be recovered and reused several times without loss of activity even under harsh conditions. Moreover, PI Pd is highly resistant to poisoning by sulfur.