This invention relates to a thermal sensitive automatic clutch for automobile fan. The outer fringe of left half clutch is conic, and can match with inner conic trough in the right half of clutch. The clutch is hooded on hollow shaft through bearing and hellow shaft. The right end of the shaft has two thermal sensitive memory alloy springs with different setting temp. points set up. The said springs are set on the inner cavity of water pump blade wheel. As the temp. of cooling water exceeds the setting temp., the spring is extended to make the tension rod driving the left half clutch to overcome the elastic force of balancing spring and engages with the right half clutch, so the fan rotates. Otherwise, the clutch disengages and the fan stops. The second thermal sensitive spring can continue to work in case of the first thermal sensitive spring is out-of-openation, so that the engine can not be damaged due to overheating.