The work aims to study the correlation between the size and quality of juicy peach and explore a reasonable grading method, so as to provide theoretical basis for grading, storage, transportation and production of high-quality juicy peach. "Yulu" juicy peaches were used as test materials to measure the weight, transverse diameter, vertical diameter, total soluble solids (TSS), titratable acidity (TA) and TSS-TA ratio of single peach. Factor-Cluster analysis was carried out to these indexes. There was no significant correlation between size indexes (weight, vertical diameter and transverse diameter of single peach) and quality indexes (total soluble solids (TSS), titratable acidity (TA) and TSS-TA ratio). Two principal components were extracted through factor analysis and their cumulative variance contribution rate was 78.401%, thus comprehensively evaluating the quality of juicy peach instead of original indexes. The peaches were classified to 4 grades by cluster analysis and the quality indexes of peach fruits of all grades showed gradient changes. Factor-Cluster Analysis is a reasonable grading method for Juicy peach, which conforms to the actual production and consumption demand.