Abstract: A magnetic rotary power source which can provide rotary power without energy consumption is disclosed. The power source includes a housing with two parallel spindles. Each spindle is disposed with a gear. The two gears have the same diameter and engage with each other. Each gear is disposed with a permanent magnet. The two magnets are arranged in a specific angular relation, and outer ends of the magnets are the same pole to generate repulsion. When one of the gears is rotated to make the magnets approach, the two gears will automatically rotate by the repulsion between the magnets. The two gears will continuously rotate when they rotate one revolution to make the magnets approach again. Thus, the gears can go round and round repeatedly.