This study has been focused on the influence of the metallic mold cooling effects on the solidification structures and the mechanical properties for Al-10%Si alloy castings by the variation of pouring temperatures, metallic mold temperatures and Cooling part of metallic mold. The dendrite arm spacing of Al-10%Si alloy was decreased with increasing cooling rate. In case of bottom cooling of metallic mold, DAS was appeared to be 20-22㎛ and in the middle cooling, it was increased to 36-40㎛. The DAS decreased proportionally with(cooling rate)＾(－3/2) at pouring temperatures 680℃ and (cooling rate)＾(－½) at pouring temperature 760℃, but it was proportionally increased to(local solidification time)＾(½－⅓) at pouring temperature 680℃ and 760℃. The maximum tensile strength of Al-10%Si alloy casting was obtained in case of bottom cooling of mold at pouring temperature 680℃ and metallic mold temperature 320℃.