Abstract: A profitability-evaluating system (10) for a medical drug candidate under development comprises a data set-creating subsystem (100) and a management index-calculating subsystem (200). The data set-creating subsystem (100) includes a sales amount-estimating section (110), an Cost-estimating section (120), a net present value (or NPV)-calculating section (131), an internal rate of return (or IRR)-calculating section (140), a repetitive calculation section (150) for creating a data set by fluctuating the respective values determined by the estimating sections and the calculating sections, within predetermined distribution widths, and a data set-recording section (160). The management index-calculating subsystem includes a volatility-calculating section (201), an option value-calculating section (202) and a project value-calculating section (203).