Provided is a composition of detection agents for living cells, especially epithelial tumor cells； the composition contains 0-5% folic acid, 0-10% folic acid complex, 0.01-5% methylene blue, 0.1-10% carbohydrate reducing agent, 2-6% acetic acid, and 3-95% water. Also provided is a preparation method for the composition of detection agents and kits containing the composition of detection agents.
