We need more information before making any kind of recommendation. How long have you had this tree? Were there any other symptoms before it  dropped its leaves? Did the fruit form fully before it went bad? Where is it situated? Are you having trouble with any other  trees on your property?
Even with that we might not be able to be definitive but at least might send you in the right direction?

Thanks for getting back to me. The leaves turn yellow , in fact that is happening now. The fruit fully forms before rotting but does so as the cherrie turn red . No trouble with other trees . Hope this helps 
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The fact that this occurs every year suggests that there could be a cultural reason. Leaves can turn yellow and drop due to too much water. Is the cherry tree in a low lying area that does not drain well? 
There are also cherry leaf spot diseases that can cause yellow/leaf drop and rotten fruit. Cherry tree leaf spot, caused by the fungus Blumeriella jappi, is a disease of cherry foliage and fruit. The fungus favors wet, humid conditions for infection and temperatures between 60 to 68 degrees F. Small purple to brown leaf spots, leaf yellowing, leaf drop and small holes where leaf spots initially formed identify cherry leaf spot on foliage.  I would suggest that you take in a sample of the leaves, twigs and fruit to your local extension office and/or send a sample into the C. Wayne Ellett Plant and Pest Diagnostic Clinic:    https//ppdc.osu.edu/submit-sample