This research was conducted to establish an evaluation system for the maturation quality of longan fruit based on the quality components and their relationships between each other. 30 varieties of longan and 43 indices for internal and external quality were chosen to be determined, and by applying multivariate statistical analysis, the evaluating results and predictive formulas for different types of fruit quality, as well as the discriminant formulas for the fruit comprehensive quality, were all studied. The results showed that the common factors were simplified as expected with their interpretive indices screened for 4 types of quality including the apparent traits, economic traits, arial quality and comprehensive quality of the ripened longan fruit. The 4 models used for predicting the scores of 4 types of quality and their corresponding database for the effective evaluation indices were all established, from which the predicted scores and the corresponding comprehensive scores from the factor analysis were all significantly relative with each other. Lastly, according to the scores for the comprehensive quality, the 30 varieties of longan were classified into 3 types, namely, low-sugar and large-size, high-sugar and medium-size, and high-sugar and small-size. Taking the two types of effective evaluation indices for the natural attribute and application value respectively as the variables, 3 types of varieties were all self-validated and cross-validated by discriminant analysis with high accuracy, which shows that the value assessment system for the practical application of longan fruit can basically meet the common needs of natural and applicative classifications. In conclusion, the evaluating indices for the comprehensive quality of longan fruit consist of glucose content, watery surface of arial, edible rate, average fruit mass, TSS and arial thickness rate, but, with the view of the characteristics of the existing varieties, the 7 indices cannot all reach the optimum level in a same variety, at least so far.