Cotton boll worm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is an important polyphagous pest throughout the world. Due to the adverse effects of chemical pesticides, alpha-amylase enzyme inhibitors in insects have been noticed as an alternative method for the pest management programs. In this project, whole gut of the fourth instar larva was dissected and the enzyme extract was pulled out. After removing seed protein extracts of Prosopis farcta and Cicer arietinum by sodium chloride 0.1 M, the effect of four different concentrations of both seed extracts (1.48, 1.2, 0.87 and 0.42 μg) were studied on alpha-amylase activity of boll worm. According to the data, the protein extract of P. farcta had greater ability to inhibit cotton boll worm amylase. Enzyme assays in the presence of different concentrations of C. arietinum and P. farcta extracts showed enzyme inhibition in a dose-dependent manner. The maximum enzyme inhibition was in pH 9. Zymogram analysis confirmed quantitative enzyme assay and showed a sharp reduction in the band thickness during the amylase inhibition. Consequently, the seeds of both P. farcta and C. arietinum, had the potential to be considered as effective and important sources of alpha-amylase inhibitors and noticed as substitutes for chemical pesticides in the near future.