ADC can reduce the adverse effects of the cytotoxic anti-tumor agents and improve the selectivity of tumor treatment. In addition, it serves as a better solution to deal with the drug resistance of targeted monoclonal antibodies. Its emergence fills the gap between antibody drugs and traditional chemotherapeutics, improving the drug specificity and the therapeutic window. As one of the pioneers carrying out the development and research of ADC in China, we have completed structure, polymorphs confirmation and impurity structure confirmation for some toxins, linkers and toxins-linkers. We have obtained the manufacturing process with stable quality through the implementation of a multi-chiral control strategy, thus achieving kilogram level supply.