Technical Abstract: In 2001 USDA officials at U.S. ports of entry intercepted a large number of diseased Chinese Ya-Li pears, the disease appearing to be caused by an Alternaria. These interceptions raised concern because the disease was unknown in the U.S. and the export workplan, which contained mitigative measures for A. gaisen and A. alternata, was ineffective in preventing the entry of diseased pears. To determine the identity of the etiologic agent of the disease, single sport cultures were established from intercepted fruit and were characterized by pathogenicity to wounded fruit, conidial morphology and pattern of sporulation on PCA, 1/2 PCA, hay and V8 juice agars, RAPD fragment pattern analysis and species-specific PCR. Comparison of morphological and pathological characters and RAPD fragment patterns indicated the disease likely was caused by more than one Alternaria, and that none of the isolates from intercepted Ya-Li fruit was A. alternata or A. gaisen. Species-specific PCR assays also demonstrated that no isolate from Ya-Li was A. gaisen or A. 'mali'. Based on these data and the absence of a description of at least one of the taxa involved, a new species, Alternaria yaliinficiens R.G. Roberts, sp. nov, is described, and the disease caused by this and other species of Alternaria on Chinese Ya-Li pears is referred to as "chocolate spot of Ya-Li pear" to distinguish it from black spot of Japanese pear.