The PBSDD technology is a specific application of PFSC in drug discovery. Starting from structures of molecule and protein, or even therapeutic target, the PBSDD technology is able effectively to screen one-dimensional PFSC-PDB database, probe new indications for approved drugs, drugs in development or chemical components from natural products, and help better understanding mechanisms of drug pathway on a molecular level. With quantitative assessment for drug binding sites, the PBSDD technology is able to provide the lead information for multiple targets in biologic inhibition, stimulation, toxicity or site-effect. The PBSDD working flow is shown in Fig 2. With PBSDD technology, can help our clients in drug discovery more focalize the targets, which should greatly reduce time and cost for pharmaceutical companies.