The conformations of Anabaena Sp. lipoxygenase (ana-rLOX), such as secondary structure, helical structure, turn structure, and disordered structure were studied in different pH buffers. The correlation between the activity and conformation of ana-rLOX was studied. The results showed that the optimal pH and the most stable pH of ana-rLOX were 9 and 7. The enzyme activity was correlated with the content of helical structure, turn structure, and disordered structure. The enzyme activity positively correlated with the helical structure and turn structure while the enzyme activity negatively correlated with the disordered structure under the pH value between 6 and 9. The enzyme was most stable when the contents of helix, sheet, turn, and random structures were 20%-30%.