One hundred cases of heavy area rainfall greater than 50mm from 1971 to 2000 in the six drainage areas of the upper reaches of the Changjiang River are analyzed , the 24hr′s forecast indexes of every drainage area are developed. Automatic differentiating T213′s forecast products correspond to the indexes by computer, the 24hr′s?48hr′s forecast of heavy area rainfall in the six drainage areas are made. Operation using from June to July in 2002 was run. The results show that the method has the better forecasting ability to heavy area rainfall, and the meteorological interpretation of T213′s products is feasible.