The influences of water-to-binder ratio, binder type and exposure time on the surface chloride concentration C_s,ts of concrete exposed to marine tidal and splash zones were investigated systematically in this study based on 304 sets of field test data selected from different sites around the world. Then, the correction factors of four binder types can be determined using the two-phase multiple nonlinear regression technique, including the ordinary Portland cement, fly ash, slag and silica fume. Finally, an improved model for C_s,ts was developed. The applicability of the improved model for C_s,ts was validated in comparison with existing models and field test data. Analysis results show that the surface chloride concentration increases linearly with water-binder-ratio, while the influence of binder type on C_s,ts cannot be ignored. Moreover, C_s,ts increases over exposure time exponentially, which appears a fast increase in the first 5 years and then becomes constant.