Provided are a platinum complex and a liposome thereof, and a use thereof. The platinum complex contains a carboxyl group having pH sensitivity, wherein in a comparatively low pH environment (such as in tumour tissues), the carboxyl group is liable to deprotonate, facilitating an improvement in the drug release inside tumour tissues and improving the therapeutic effect of drugs. In addition, the platinum complex can be well combined with the membrane materials of lipidosomes, so as to improve the encapsulation ratio and drug loading capacity of lipidosomes. Experiments indicate that the lipidosomes of the platinum complex can reduce the toxic and side effects of drugs and increase the therapeutic effect thereof.