Objective: To evaluate the diagnostic value of multi-slice spiral CT perfusion imaging for acute pancreatitis (AP). Methods: Eighty-six AP patients were divided into 5 groups according to the Balthazar scoring system after 64-silce spiral CT perfusion imaging examination. The CT perfusion indexes including blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability-surface area product (PS), as well as the clinical biochemical parameters including serum and urine amylase (AMY) level, C-reactive protein (CRP) and hematocrit (HCT) among the groups were compared, and the correlation analyses between the perfusion indexes and clinical biochemical parameters were also performed. Results: Among the AP patients, both BF and BV values were decreased as the Balthazar score increased, and both values were significantly lower in severe AP patients than those in mild AP patients (P=0.013 and 0.025); the serum and urine AMY levels were increased at the early stage, but gradually decreased in the advanced stage of the disease, while CRP and HCT levels showed a continued increasing trend with increase in Balthazar score, and all the differences between groups had statistical significance (all P<0.05). Correlation analyses revealed that either BF or BV value had a significant negative correlation with HCT value in AP patients (r=–0.515 and –0.624, both P<0.05). Conclusion: The perfusion indexes BF and BV have correlation with biochemical parameter HCT, thus, spiral CT perfusion scanning has a certain value for diagnosis and severity grading of AP.