Further studies on the phase transition mechanism of LiIO3 at normal pressure have been made by means of DTA, heat-treatment, and powder X-ray diffraction. There are three phases of LiIO3, β,η,δ, existing relatively stably at high temperatures and they can directly melt respectively. Their melting points are as follows: phase β, 432℃; phase η, 421℃; phase δ, 416℃. The melting points, thermal processes and the exiting temperature ranges ail show that the order of their thermodynamical stability is: β>η>δ. In dry air and at room temperature, the phase ζ of LiIO3, which changes to phase β when it is heated to 335℃ at 10℃/min, stands long periods of time without any change as well as phase α and β . In the existing temperature range of α -LiIO3, phase ζ does not transform into phase α although it is heat-treated for a long time. The temperature of phase transition of ζ to β is higher than that of α to β. The existence of phase β in the phase ζ has a promotive effect on the phase transition of ζ to β just as the case of α to β. The existence of phase ζ in the phase α has also a promotive effect on α to β . The phase θ, like the phase γ. is also an intermediate metastable phase in the phase transition processes of LiIO3.