The following research will have a look on business links between cleantech industry´s categories. Apparently there are eleven sub-industries within the cleantech industry. The research looks at different companies in these sub-industries and figures out how theyare related. The relations would be buyer and seller relationships. A number of 20 companies from Swedish cleantech industry have been selected for this purpose. For each company products have been studied to allocate the company in one of the elevensub-industry of cleantech industry. The customers for each company were needed to know where these clean products are consumed. Also for each customer the proper class in cleantech industry should be designated. In the conclusion, the links between the eleven sub-industries of cleantech industries are recognized and remarkable point are pointed out.