A corporate business support system includes a population forming unit, a change keyword extraction unit, a co-occurrence word extraction unit, and an output unit. The population forming unit forms a population for each type of element of 3C (customer, company and competitor) and for each of predetermined periods. The change keyword extraction unit extracts a change keyword based on the formed populations. The co-occurrence word extraction unit extracts a change keyword included in both populations as a co-occurrence word among the extracted change keywords in a combination of a company and a customer and a combination of the company and the competitor which are elements of 3C. The output unit outputs text including the extracted co-occurrence word in association with one of the combination of the company and a customer and a combination of a company and a competitor.