Abstract: The process of the GM (1,1) model’s construction,the accuracy inspection and the correction methods are presented.Using the grey correlation theory  the points which have the similar rules of sedimentation are classified in order that only a few monitoring points’ sedimentation condition is used to estimate the other related points’ and improve the economic benefits.Take No. 3 route Yantang station in Guangzhou Metro Station  as an example.That GM (1,1) model forecasts the average error of 4.19 percent,and calculation of correlation is in good agreement with the actual situation.

Key words: prediction of foundation sedimentation, grey model, correlation