The hydrolysis of bis(p-nitrophenyl phosphate)(BNPP) and p-nitrophenyl phosphate (NPP) were strongly promoted by the mononuclear LaIII[(N,N′-bis(3-carboxyl)-2-hydroxysalicylidene)ethylenediamine] and the hetero-dinuclear CuIILaIII[(N,N′-bis(3-carboxyl)-2-hydroxysalicylidene)ethylenediamine] complexes at 35 °C in 50% aqueous DMSO. The results indicated that the hetero-dinuclear CuIILaIII complex exhibited a relatively higher catalytic function on NPP hydrolysis, while the hydrolysis of BNPP was slightly more efficient in the presence of the mononuclear LaIII complex than that in the presence of the CuIILaIII complex, and this case was discussed by the different spacer requirements for NPP and BNPP hydrolysis. In addition, widely differing pH-rate profiles were obtained: saturated curves for NPP hydrolysis and bell-shaped curves for BNPP hydrolysis, and thus different kinetic treatments were employed to obtain the relative parameters.