In the Pre-Qin Dynasty and the Han Dynasty,"shi(视)" was often used to express "eye contact with people or things"."Kan(看)" originated from the Han Dynasty,and literature cases were rarely seen.In the Period of Wei-Jin-Southern-Northern Dynasty,"kan(看)" was in the phase of development,and literature cases were gradually increased.However,it was not too much more than the traditional "shi(视)".Since the Tang Dynasty,"kan(看)"continued developing,and there were more and more literature cases,with "shi(视)" replaced in spoken language.But "shi(视)"still dominated in the written language.