The purpose of this study is to develop a theoretically and methodologically sound bidimensional affective scale measuring mathematics anxiety with high psychometric quality. The psychometric properties of a 14-item Mathematics Anxiety Scale-Revised (MAS-R) adapted from Betz's (1978) 10-item Mathematics Anxiety Scale were empirically analyzed on a college sample for its internal consistency reliability, parallel-item reliability, and construct validity. In addition, the bidimensionality of MAS-R was verified through the two-factor measurement model that fitted to the data significantly better than the one-factor model. Therefore, MASR is a psychometrically reliable and valid instrument for measuring bidimensional mathematics anxiety. Implications of the bidimensional affective scale in measuring mathematics anxiety are discussed. (Contains 2 tables.)