Abstract: It has been nearly a hundred years since radium was first isolated and used in the Curie laboratory, initiating the research on radiation chemistry of heavy ions in aqueous solutions. The radiochemistry of heavy ions in aqueous solutions is extensively applied across several areas, such as nuclear reactor safety, deep space exploration, heavy ion therapy and medical isotope production, etc. In the realm of nuclear reactor safety, the analysis of radiation effects induced by radioactive materials in various operational scenarios is facilitated by aqueous solution heavy ion radiation chemistry, providing crucial insights for reactor safety control. Furthermore, by examining the biological impacts of heavy ion radiation from cosmic rays, radiolysis research offers invaluable information for radiation protection during deep space exploration missions. With the continuous advancement in proton and heavy ion cancer treatment technology, a comprehensive understanding of their underlying mechanisms and reaction kinetics has become a pivotal objective in the study of heavy ion radiation decomposition in aqueous solution, thereby furnishing a theoretical framework and data-driven guidance for cancer treatment and treatment plan refinement. The widespread application of radiochemistry of heavy ions in aqueous solutions underscores its significant role in advancing technology and ensuring safety in various areas. The track structure effect is the pivotal scientific question concerning the heavy ion radiolysis of aqueous solutions. In order to clarify and interpret the track structure effect of radiolysis of heavy ions in aqueous solution, a series of experimental studies has been performed and several theoretical models have been proposed. Taking advantages of heavy ion accelerator facilities, the track structure effect can be investigated through the study of the yield and kinetic processes of free radicals and molecular products under various linear energy transfer (LET) radiation conditions. In this article, the decomposition process of aqueous solutions due to ionizing radiation and the concept of track structure are firstly introduced. Then, after addressing the experimental investigation methodologies for heavy ion radiolysis of aqueous solutions, including steady-state and transient radiation perspectives, those representative heavy ion facilities available for heavy ion radiolysis study in the world are summarized and the major advancements and achievements in recent years are reviewed. The track structure effect of radiolysis of heavy ions in aqueous solutions is described in detail in terms of experimental research. Finally, the significance and future applications of heavy ion radiolysis in aqueous solutions in interdisciplinary fields, encompassing both basic and applied sciences have been discussed.