Abstract: Large blackouts are usually caused by a complicated sequence of cascading failures. Initial failures weaken the system and cause further failures, which further weaken the system and so on. This study investigates the blackout that occurred on 9th August in the Jordanian Power System. For modeling the blackout, a base case was established by creating a power flow simulation for the system with both of Egypt And Syria links. The analysis shows that the blackout has occurred as a result of full stoppage of Aqaba TPS (Thermal Power Station) and false switching-off the Egypt power system link, as a result, frequency dropped below 49.0 Hz, which in turns, caused a Frequency Load Shedding (FLS) in Syria power system and consequently, the blackout of Jordan power system. The study shows that the blackout could be avoided if the proposed arrangement of emergency automatics had been in use.