Bacillus thuringiensis is a gram-positive bacterium that produces d-endotoxins active against diverse insect pest species and other invertebrates, which cause extensive agricultural damages in the world. The cry genes isolated from B. thuringiensis have been widely used to develop transgenic plants with enhanced resistance to specific insect pests. Despite of the toxins (Cry proteins) B. thuringiensis of the diversity, the rapid molecular evolution (DNA shuffling) has been contributed to generate more potent and specific Cry proteins against diverse agricultural pests. In this context, the present work aimed to develop new mutant for Bt toxins with enhanced activity towards the main insect pest of maize and cotton, the fall armyworm (Spodoptera frugiperda). A library was constructed using the recombination of a new cry8 gene combining DNA shuffling and Phage Display techniques. The gene denominated, cry8H, was initially amplified by PCR using specific primers containing the Sfi I restriction site and submited to DNase I fragmentation. The products of this reaction (30-50 bp fragments) were submited to a new PCR reaction without primers in order to obtain new recombinant genes. The recombinant genes were digested by Sfi I, subcloned in the pCOMB3X phagemid and expressed in Escherichia coli (XL1 Blue) generating a combinatory library of mutant genes cry with 10⁵ transformants. The clones obtained were screened for Phage Display using S. frugiperda gut ligands and the select molecules exhibited a higher insecticidal activity ranging from 2 – 6 times in relation to the wild type. This result demonstrated that the combination of DNA shuffling and Phage Display techniques is efficient a tool to generate new cry genes encoding insecticidal proteins with potential use in the S. frugiperda control.