Nostoc flagelliforme was cultivated on three solid bed-materials which have different wettability. The results show that the wettability of solid bed-materials is very important to the need for water in N. flagelliforme, and also greatly affects photosynthetic activity, polysaccharide secretion and the morphology of the cells. Glass residue has the best wettability, followed by sand, and then nylon6 (PA6). We show that only sand is suitable for the growth of N. flagelliforme. When cultivated on sand for 100 days, the cells maintained a typical rosary-like shape. On glass residue, two to three vegetative cells formed a group with slime. On PA6, cells were in the form of loose group with slimes. N. flagelliforme is applicable to desert control as it cannot only grow on the sand, but also adhere to sand to form a biological crust.