We examine how the approaching international lease accounting regulations influence credit rating of particular airfreight company, we capitalize all of still effective operation lease agreements commencing in 2002 and expired on 2026. In particular we use actual operation lease data, not only the disclosed with off-balance sheet. Our results suggest that, on average, capitalization of over 12 months term operation leases, dramatically alter capital structure. Results either reports a positive impact on weighted average cost of capital WACC, credit rating is a financial risk assessment measurement used by credit holders, investors, and analysis, our results is consistent with the lease accounting standard sitters point of view; investors and credit holders have the right to obtain a full transparent picture about firms lease activities in benefit of all parties. We also find some evidence that the positive change in WACC is related to the increasing portion of capitalized lease liability accompanied with an escalating decreeing in conventional debt, in certain conditions, this result suggests that financial lease has the advantage over conventional debt. Keywords:lease accounting reform, capitalization, financial risk, cost of capital, credit rating