Abstract： The electron irradiation effects on the crystal structure of α-lithium iodate (α-LiIO3) have been observed by TEM. Under the irradiation of medium-intense electron beam with energy 100 KeV, α-LiIO3 transforms into γ-LiIO3 at first and then into Li2O and an other new type of Li-O compound which is probably a nonstoichiometric one and re-fered to as X compound. If the irradiation is carried out with more intense electron beam, α-LiIO3 crystal melts quickly. In that case, either a decrease in intensity of electron beam or a break in irradiation leads to recrystallization of the melted substance in the form of X compound which gradually transforms into Li2O and metal Li under subsequent electron irradiation. The phase tansformation form X compound into Li2O is reversible to certain extent. Besides, it is found that the electron irradiation effects on the structure of α-lithium iodate monocrystal is clearly anisotropic.