Concrete service life will be different depending on curing conditions. In this study, two levels of water-binder ratio and maximum coarse aggregate size and curing conditions of which sealing curing and standard curing with pH 11.8 level and clean water curing with pH 6.0 level were carried out. We examined compressive strength and chloride diffusion characteristics. Based on the results, to design service life of the concrete, durability design method especially Duracrete were applied. As a result, the compressive strength appeared higher when lower water-binder ratio, and the smaller maximum coarse aggregate size cases. In details, the 20mm maximum coarse aggregate size concrete with standard curing with pH 11.8 level was the highest strength property, then sealing curing, and clean water curing with the pH 6.0 level in this order. These results showed that with maintaining the alkalinity of the concrete to prevent corrosion properties, calcium hydroxide have the osmotic effect with a leaching into clean water with a lower pH. When it comes to chloride penetration period of concrete, the sealing curing due to external exposure and drying effects including the relatively large pores is the most advantageous, then the standard curing with the level of pH 11.8, and clean water curing with the pH level of 6.0 in this order. To sum it up, to assess durability of the concrete, in addition to consider the ordinary values which affecting durability, if the curing conditions of concrete also will be considered, we can ensure improved reliability.