The liquid‐glass transition of LiI has been investigated by means of the constant‐temperature and constant‐pressure molecular dynamics method. Because LiI is one of the most simple examples of the coulombic system and the most contrasted combination of the cation and anion among all alkaline halides (the mass ratio of I to Li is 18.3 and the ionic size ratio is 3.6), we have expected to see the ionic motion most drastically. We calculated both static and dynamic properties with microscopic analyses for ionic motions. In the vicinity of the glass transition, the mean‐square displacement shows a non‐t‐linear behavior, sometimes called a subdiffusive behavior, and the incoherent scattering function are well fitted by ‘‘stretched exponential’’ function. The non‐Gaussian parameter as a function of time has a large maximum, and the product of the maximum value and the corresponding time increases sharply as approaching the glass transition. All these anomalous characteristic behaviors, as well as those found for the binary soft‐sphere system, are in good agreement with the prediction of the trapping diffusion theory. We discuss the validity of this theory.