Cancers cause death. Recently, many studies focus on the localized treatment to reduce the side effects of chemotherapy. In this research, the cisplatin has been successfully deposited on pure Mg specimen, degradable and promising for the tumor treatment by its local sustaining release to prevent the cancer from metastasis and even to achieve its apoptosis. In the experiment, the cathodic polarization tests coupled with electrochemical reactions in various concentrations of cisplatin solutions were analyzed to speculate the deposition mechanism of cisplatin, spectrophotometer (UV visible spectrometer) to measure cisplatin loading and release, Fourier transform infrared spectroscopy (FTIR) for chemical bonding of composites, field emission scanning electron microscope (FESEM) and focused ion beam (FIB) to observe surface and cross-section morphology, and energy-dispersive X-ray spectroscopy (EDS) to analyze constituent elements. The drug, cisplatin, is deposited on the pure Mg through exchanging Cl^- with OH^-, produced by the electrochemical method, to form strong hydrogen bonds for attracting one another. Besides, the drug loading on the post hydroxyapatite coated degradable Mg specimen with high porosity can be enhanced from 34.65 to 84.93 μg/cm² and the drug sustaining release last for 3 weeks, which is promising for future clinical applications.