Interstratified Ni-serpentine/smectite = 2/1 compound was described by transmission electron microscopy (TEM) for the first time. The image of the lattice fringe coincided with the result of simulation, and it is clearly different from that of chlorite/smectite = 1/1 mineral which has a similar periodicity in Xray diffraction pattern. The image of domains curving to the direction of their serpentine-part, suggested that the surface of the particle was mainly consisting of Si-O sheets.