The performance development of metakaolin(MK) cement paste was examined from early hydration stage to curing for 28d by electrochemical impedance spectroscopy, mercury intrusion porosimetry and compressive strength test. The variation of electrochemical parameters of MK cement paste with curing age was analyzed. A new equivalent circuit model was provided, which can take both the dispersion effect and the diffusion process at cement paste/electrode interface into consideration. The relationship between electrochemical parameters, compressive strength and pore structure parameters were discussed. The results show that MK can promote the hydration process of cement paste. The charge transfer resistance(Rct1) of MK cement paste obtained by the equivalent circuit model can well reflect the compressive behavior of MK cement paste. Porosity of MK cement paste shows a negative correlation with charge transfer resistance Rct1 and high frequency impedance modulus |Z|1 of MK cement paste.