Abstract: The authors studied the basic theories of statistics method of multivariate information in time domain and characters about variogram in the first. Based on the observation data of BOD,COD and DO from Zhalong wet land in recent five years,the method of multivariate information was used to predict the trend of the water quality in 2005-2009. Under the condition of minimum variance, this kind of method could make the estimation unbiased. The result implied the changed trend of DO and BOD content in water was not obviously, but the COD content moved upward obviously, and water quality was changing. So it is necessary to reduce the quantity of foul water into wetland and strengthened to treat foul water in order to prevent water quality to be worsen.

Key words: Krige method in time, surface water, forecast of water quality