High-pressure dense-phase CO2 transportation is the main approach for transportation of CO2 in China. During the transportation process, CO2 is in a high-pressure dense phase. If CO2 leakage occurs in such a case owing to line equipment damage, the low-temperature high-speed jet flow will be hazardous for human lives and property. To study CO2 leakage, an experiment was conducted to examine the impact of a dense-liquid CO2 jet during accidental releases. The impact value was measured for different nozzle sizes, inner pressures, and distances. Therefore, studying the mechanism and effectively evaluating the consequences and impact of the accidental leakage of high-pressure dense-phase CO2 are important for ensuring the security of its transportation. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.