Abstract: A modularized custom-developed software package producing method and system is proposed, which is capable of automatically producing a custom-developed software package based on customer-designated specifications; and which is characterized by the provision of all required functional and data objects as modularized objects, including a software core module object, a group of functional module objects, and a group of custom-made module objects, which can be selectively chosen to be gathered and combined into an integrated code package serving as the intended custom-developed software package. The proposed method and system allows the overall software development process to be less laborious and time-consuming and thus more efficient to implement, and can help prevent confidential business documents and data files that are embedded in the custom-developed software package from unauthorized access and tampering.