Evaluation method and evaluation device for similarity of source codes

The invention relates to an evaluation method and an evaluation device for similarity of source codes. Calculation amount for analysis of code clone increases with large-scale software. The evaluation device for similarity of the source codes comprises a development achievements analysis unit (21) for extracting source code list constituting the software, a corresponding relationship analysis unit (22) for comparing a comparison reference source code list (44a) and a comparison target source code list (44b) and analyzing corresponding relationships of the both, a comparison object determining unit (23) for determining a comparison object of a comparison target source code (44b) contained in a comparison reference of the comparison reference source code list (44a) from the comparison target source codes (44b) according to the corresponding relationship, a similarity calculation unit for calculating the similarity between a comparison reference source code (44a) and a source code determined by the comparison object determining unit (23), and an output unit (15) for outputting combination of the comparison reference source code (44a) and the similarity.