The application of in-situ synthesized materials,forming mechanism,in-situ materials classification and using in leather-making of the in-situ polymerization materials were reviewed.The concept of dynamic in-situ reactive functions during the process of in-situ synthesize has been propounded,and the synergistic effect between the reactants also has been discussed.At last,the advantages and disadvantages of in-situ synthesis technology were summarized.The prospective of in-situ synthesis was developed in leather-making.