Abstract: The disclosure relates to an improved Oil Red O staining solution, which consists of 0.5% of Oil Red O, 50% of ethanol, and 5% to 10% of salicylic acid. The staining solution does not contain organic solvents toxic to human bodies and has good safety and no toxic effect. The disclosure further relates to an Oil Red O staining method for cells or tissues, which is simple in operation, short in staining time, and easy to stain neutral fat in cells or tissues, with good staining effect and clean background. This method does not use isopropanol, which is safe and convenient and is suitable for popularization and application in laboratories.