We investigate the chaotic inflationary model using the two-loop effective potential of a self-interacting scalar field theory in curved spacetime. We use the potential which contains a non-minimal scalar curvature coupling and a quartic scalar self-interaction and which was found in Ref. [1] . We analyze the Lyapunov stability of de Sitter solution and show the stability bound. Calculating the inflationary parameters, we systematically explore the spectral index ns and the tensor-to-scalar ratio r , with varying the four parameters, the scalar-curvature coupling ξ0 , the scalar quartic coupling λ0 , the renormalization scale μ and the e-folding number N . It is found that the two-loop correction on ns is much larger than the leading-log co...