| Antibody-drug conjugates consist of 3 main parts which include the "bullet" drugs (cytotoxic drugs), antibodies and the linker connected the antibodies and drugs. As a new type of drug, it combines the targeting specificity of the antibody with the cytotoxic effect of small molecule drugs, thus it has been the research hotspot in the field of cancer research. According to its source of cytotoxic drugs, it could be divided into two types: land-derived drugs and marine-derived ones. In this paper, these two types antibody-drug conjugates are reviewed. Besides, the key technique of ADCs including the specificity of the target, the affinity of antibodies, the high performance of cytotoxic molecules and the appropriate choice of the linker are summarized.