The　hexagonal-hole　grid　flocculation　system　is　very　efficient　to　deal　with　high　turbidity　water　of　850　NTU　and　the　color　of　2300　PCU.　The　best　conditions　are　determined　through　adjusting　grid　arrangements,　concentration　and　dosage　of　flocculating　agent.　When　the　water　velocity　of　flow　is　100　L/h,　the　grid　2,　1,　3　module　order　is　the　best　one.　The　water　turbidity　decreased　to　19.5　NTU　and　color　to　110　PCU,　the　removal　rate　of　turbidity　is　97.0%　and　that　of　color　is　95.2%.　The　average　effective　mass　density　ft　of　floe　is　6066　Kg·m　-3,　the　average　equivalent　size　dST　is　346.9μm,　the　average　free-for-speed　V　is　13.24　mm·s-1,　two-dimensional　fractal　dimension　Df　is　2.70.　©　2010　IEEE.