High temperature low cycle fatigue tests of new heat resistant aluminum alloy were conducted in this study. Al-Mg-Si-(Co, Ni) aluminum alloy consists of Al matrix, small amount of Mg<SUB>2</SUB>Si and (Co, Ni)<SUB>3</SUB>Al<SUB>4</SUB> strengthening particles. Low cycle fatigue tests controlled by total strain were performed with strain ratio (R)=-1, strain rate=2x10<SUP>-3</SUP>s<SUP>-1</SUP> at 250℃. Fatigue limit of low cycle fatigue of this alloy showed plastic strain amplitue(Δε<SUB>ps</SUB>) of 0.22% at the 10<SUP>3</SUP> cycles. This value was superior that that of conventional aluminum alloy such as A319. Results of fractographical observation showed that second phases, especially (Co, Ni)<SUB>3</SUB>Al<SUB>4</SUB> particles, could act a strengthening role for low cycle fatigue behavior. It is also attempted to clarify the mechanism of high temperature low cycle fatigue behavior of Al-Mg-Si-(Co, Ni) alloy related with its micorstructure and energy dissipation anaysis.