Based on the solar radiation observations from CE-318 sun-photometer's 936 nm channel and the relation of water vapor amount and transmissivity,the instantaneous technique is used to retrieve the atmospheric column water vapor amount on the west coast of the Bohai sea gulf.The results show that,using sun-photometer's 936 nm channel observations to retrieve atmospheric water vapor amount is feasible,but only on clear days.Atmospheric water vapor amount on the west coast of the Bohai sea gulf showed complicated temporal variations throughout a year with different diurnal variation patterns on clear days in defferent saesons.