Copper slag is a by-product yielded from a copper refinery. The annual amount of copper slag in Japan is two million tons. The copper slag has been used for cement material, sand blasting, reclamation and so on. However, most of the copper slag is stacked high as waste since the production exceeds demand. This study on the application of copper slag as fine aggregate for concrete has been started with the expectation of large amounts of consumption. Many researchers have already found it possible to use a copper slag as a concrete aggregate. However, it also has been clear that the concrete with copper slag has some problems. One of them is excess bleeding attributed to the glassy surface of copper slag. Another problem is the delay of setting time of concrete with copper slag nevertheless it produced at the same refinery. The delay of setting time is more than one week in some cases although the durability in concrete is not affected by it. In this paper, the strength, setting time and durability of concrete with copper slag is clarified. It is shown that the delay of setting time does not have a negative influence on durability. Furthermore, the solution will be given in this paper.