The purpose of the modified health belief model (MHBM) is to identify the important social cognitive variables in the personal preventive health behavior, and to develop the contents of the health education programme. However, its success depends upon the psychometric basis of the principal components in the model(MHBM).The related study to the adolescent motorcyclists without license was fully utilized to explain how to establish the standardized porocedure of the scales, and how to evaluate the psychometric characteristics of the scales. The procedure is divided into three stages, collecting the items, performing the pretest, and the formal test. We found the following results. The scales are unidimensional, and they can be named their corresponding MHBM constructs. The scales are excellent not only in the content validity, construct validity, criterion-related validity, and discriminant validity, but also in internal consistent reliability and stable (test-retest) reliability. Again, it is very important to use the open-ended elicitation questionnaire for the items of the scales partly because it can control the sampling adequacy in the content of the scales, and partly because it can accomplish the standardized procedure of the scales.