Self-assembled monolayers(SAM)with different terminal chemical groups(-CH3,-Br,-C6H5)were employed as substrates for adhesion and motility of Amphiprora alata.The adhesion was involved in the quantity of adhesion,the aggregation of diatom cell,the morphology of a simple cell and the strength of adhesion.The motility was involved in the proportion of motile cells.The adhesion and motility of the diatom cells exhibited significant difference on different hydrophilic and hydrophobic chemical functional surfaces.