Equilibrium surface tension of water soluble triblock copolymer PEO-PPO-PEO (Pluronics) has been measured to determine critical micelle concentration (CMC). The equilibrium surface tension data have been fitted with Langmuir adsorption isotherm. Dynamic surface tension (DST) of the polymer solutions has been measured at below and above the CMC. Results have been compared with the data of a typical non-ionic surfactant C₁₂E₉. Significant difference in behvaior of DST has been observed, with the P123 showing very slow relaxation below the CMC. Above CMC DST data of P123 show a long induction period. However relaxation time has been found to be comparable to C₁₂E₉. Ward and Tordai model with Langmuir adsorption isotherm has been used to fit the DST data of P123. Similarly C₁₂E₉ data from the literature has been fitted with Ward and Tordai model. A reasonably good fit has been obtained for C₁₂E₉, although the long time data deviates from the model. The model has been found to be inadequate for the triblock copolymer which has been attributed to the change in configuration of the polymer at the surface after adsorption.