One of the most important targets in alzheimer disease is Beta site amyloid precursor protein cleaving enzyme-1 (BACE-1). It is a membrane associated protein and is one of the main enzymes responsible for amyloid β (Aβ) production. Up to now, a considerable number of peptidic and non-peptidic inhibitors of BACE-1 have been developed. Recently, small molecule BACE-1 inhibitors have attracted the attention of scientists, because peptidic inhibitors have many pharmacokinetic problems. In the present study, several small molecule BACE-1 inhibitors were extracted form Brookhaven Protein Databank (PDB) and subjected to dissection analysis to achieve constructing fragments. Atom type, hybridization, and bond order were considered for generated constitutional fragments (simplified (SBDD) strategies.