Abstract: A proportion predicting system for realizing a predetermined target by mixing a predetermined number of elements at a predetermined proportion. The system includes a target characteristic extractor for extracting a characteristic of the predetermined target; an evaluating means operable upon receipt of proportion vectors, which are represented by the characteristic of the predetermined target and the quantity of each of the elements, respectively, to determine fitnesses of the proportion vectors based on the extracted characteristic of the predetermined target; and a GA processor for predicting the proportion vectors on the basis of the fitnesses according to a genetic algorithm in which the quantity of each of the elements and each of the proportion vectors are represented by a gene and a chromosome, respectively.