The effects of citral on the respiratory metabolism and glycolysis of Penicillium digitatum were determined. Results showed that citral has a significant inhibitory effect on the respiratory metabolism of P. digitatum and the superposing percentages of treatment with 1.0 μL/mL citral after addition of malonic acid, iodine acetic acid, and phosphate sodium were 15.00%, 12.60% and 30.70%, respectively. Determination of the superposition percent demonstrated that the glycolytic pathway was affected by citral. After treatment with citral at its minimal inhibitory concentration (MIC, 2.0 μL/mL) and minimal fungicidal concentration (MFC, 4.0 μL/mL), marked increases in theglucose content, pyruvic acid content, phosphofructokinase activity, and pyruvate kinase activity were observed. Moreover, a reduction in hexokinase activity was also observed. The results of this study indicate that citral affects the activity of key enzymes and the content of important intermediate products of the glycolytic pathway of Penicillium digitatum.