Objective: To analyze and compare the role of inclusive commercial medical insurances in the multi-layer medical security system of representative regions and provide references for promoting the development of inclusive commercial medical insurances as well as constructing more effective multi-layer medical security system. Methods: Three regions were selected to conduct case studies. Based on the schemes of local social medical insurances and inclusive commercial medical insurances，the reimbursement rates of the insurances at different medical cost levels were calculated. Results: Inclusive commercial medical insurances play a supplementary role when high medical expenditure is incurred，and the role is in relation to the schemes of inclusive commercial medical insurances and social medical insurances' features. Conclusion: To improve the supplementary role of inclusive commercial medical insurances，it is suggested to design the insurance coverage and treatment levels of inclusive commercial medical insurances appropriately coherent with the local social medical insurance benefits.