The aims of this study are to find out significant factors of the repetition of an offense when we predict it concerning the delinquent juveniles under the probation, to compare empirically the variation in the accuracy of the prediction which are due to the different techniques in the quantification of categories of those factors, and thereafter, to get acquainted with the useful technique for making the prediction table. The surveyed factors include not only those before they came under probation such as the life history, the personality, the environments, but also those observed, recorded by the probation officers during their probation. 136 successful cases and 59 cases a second offense are the subjects of this survey. x^2 and critical ratio technique are used for the selection of the significant factors and category. The seized significant factors are fifteen in number, and the significant categories involved in those factors were twenty two in number. Four quantification techniques are compared with one another: (1) the technique which Mr. Hayashi used for parole prediction, (2) the technique employed by Dr. Glueck to investigate the delinquent juveniles, (3) the technique which gives -1 to each of the categories which are closely related to a second offense and gives +1 to those related to a Success, (4) the way to apply Dr. R. J. Wherry's formula of weighting to the percentage of a second offense and a success, concerning each of those twenty two categories. When the score of each of those 195 subjects is calculated according to the abovementioned techniques, the accuracy of prediction can be theoretically calculated as follows : the technique (1) has an accuracy of 88%, the technique (2) 74% the technique (3) 80%, and the technique (4) 80%.The difference between the technique (1) and the other three techniques is significant (P=0.05), and there can be found no significant difference between the other three techniques.