The purpose of this research is to investigate the effect of provided forms on creating inventions. In creative cognition approach, Finke, Ward, & Smith (1992) showed that people can create products using specific object forms and exploring the forms' possible functions. Accordig to their account, these self-generated preinventive forms were more useful for creating inventions than externally provided forms. One hundred and thirty three undergraduates were divided into six groups. The subjects of five experimental groups used the provided objects made of three parts, and 1) thought of some reasons why the objects had those forms, 2) recombined the parts to the objects in imagery, 3) rotated them inversely in imagery, 4) transformed them into stable forms, 5) evaluated them on quality, novelty, usefulness, and ambiguity. The subjects of the control group generated objects using the three parts by themselves. All subjects described the features of the objects, and next, they interpreted them as some kind of inventions restricted by one of eight categories (e.g., furniture). The results showed that the subjects using the externally provided object forms with thinking of reasons or mental rotation, could produce inventions the same as the control group subjects. These subjects also could find attributes related to the purposes and functions of the object forms, and then they used them in creating products. In order for creative inventions, it is important to find the purposes and functions of the preinventive forms by which are both provided and self-generated.