This　paper　creates　and　verifies　the　mathematic　model　of　drying　shrinkage　of　C40　SCC　(self-compacting　concrete)　under　the　research　of　gray　system　theory　GM(1,　1).　It　also　gives　a　prediction　of　drying　shrinkage　of　C40　SCC　in　the　period　of　8d　tol6d.　The　result　shows　that　GM(1,　1)　is　good　to　predict　the　short　term　shrinkage,　but　the　medium　and　long-term　Shrinkage　forecasts　based　on　GM(1,　1)　need　more　training　samples　in　order　to　be　more　accurate.