Two size (20?L?27mm and 30?L?37mm) of mangrove snail Cerithidea obtusa were cultured in tanks of 100L volume with pH varied from 5-9 during 90 days. Results showed that the specific growth and daily growth rate of small size were not significantly difference among treatments (P>0,05). However, the specific growth and daily growth rate of length, width and weight of adult snails were significantly difference among pH treatments (p0.05). This study suggested that the small size snails performed best growth and survival in pH range of 8-9 and for adult snails from 6-9.