The concentration of five heavy metal  (Fe, Pb, Cd, Cu and Zn) were determine. The increasing trend of metals were observed in Muang district and summer as Pb > Cd > Zn > Fe > Cu, in rains as Pb > Cu > Cd > Zn > Fe. Amphawa district in summer  Zn > Pb > Fe > Cd > Cu, in rains as Pb > Zn > Cd > Fe > Cu and Bangkhontee district in summer as Cd > Pb > Zn > Fe < Cu and rains as Pb > Fe > Zn > Cu > Cd. The concentration of heavy metal, all kinds of contamination in surface water in Samut Songkram in the summer and rainy are difference sifnificant (sig = 0.0000) at  0.99 level by t – test. The source of heavy metal contamination in the surface water of the samut songkram province come from being use in agriculture (pomelos, coconuts and lynchee) and upstream mining, so heavy metal have been discharged to the Mea Klong river and flows though the Samut Songkhram province.