The business ecosystem shares many unique features with the biological ecosystem due to its origins. Similar to the biological ecosystem, the business ecosystem also emphasizes symbiotic relationships among symbionts (i.e., participants of a business ecosystem). In this study, we have broadened and deepened our knowledge of symbiosis in a business ecosystem, focusing on how each relationship develops and evolves through the interaction between keystone species and symbionts. We have introduced the typology of symbiotic relationships and highlighted the significant role of keystone species in business ecosystems. We defined three symbiosis types based on the analysis results: mutualism, commensalism, and parasitism. The findings indicated that each relationship continuously transitions into different symbiotic relationships as the relationship between the participants changes. The results also showed that a keystone species, a leader of a business ecosystem, can contribute to the success of a business ecosystem by strategically managing their relationship with symbionts.