Abstract:It studied the calyx end black spot affected on fruit quality through the determination of color differ－ ence， soluble solids content and fruit hardness in health and disease pear in the process of storage ，when the calyx end black rot pathogenic bacteria extracted from Korla fragrant pear disease fruit and reversed connect to healthy fruit.The results showed that the healthy fruit had higher L value than infected fruit， and infected fruit had higher a and b value.With the extension of storage period， a and b value in the healthy fruit and infected fruit was rising，while a and b value in infected fruit was always greater than healthy fruit； L value changed trendly in contrast to a and b values， and L value in infected fruit was always less than healthy fruit. Soluble solids content and fruit hardness were declining in Korla fragrant pear health fruit and infected fruit in storage process， but there was a big drop in infected fruit.