N-morpholin-4-ylmethyl-isatin-3-thiosemicarbazone(L) was synthesized from isatin by the Mannich reaction followed by a condensation with thiosemicarbazone.L reacted with MnCl2 to obtain a Mn(Ⅱ) complex{[MnLH2O]Cl2}.The structure was charaterized by 1H NMR,IR,MS and elemental analysis.