This study attempted to explore the psychological traits and brain structures of mathematically and scientifically talented (MST) students. The subjects participants were 36 MST students and 37 regular (RG) students from five senior high schools in Taipei city. Research instruments included “Otis-Lennon School Ability Test (OLSAT)”, “Basic Competence Test”, “The Me Scale”, “MRI scan” and “voxel based morphometery of SPM (Statistical Parametric Mapping)”. The data gathered were processed by t-test, Pearson correlation, and VBM. The main findings were as follows: (1) The MST students got significantly higher scores than RG students on math-science achievement and intelligent test. (2) MST students got higher scores than RG students only on the subscale of intellectual OE (TOE) and TOE was found significantly correlated with achievement and intelligence. (3) By adopting theory of Parieto –Frontal Integration (P-FIT) of intelligence which identifies a brain network related to intelligence, the researchers surmised the difference in brain information processing between MST and RG students. (4)The MST students had greater gray matter density than RG students in many left hemispheres regions, but the RG students had greater gray matter density than MST students in many right hemispheres regions. (5) Negative correlation was found between verbal IQ and gray matter density in right superior parietal lobule. (6) The results of the correlation between math scores of Basic Competence Test and gray matter density showed positive correlations in left BA 22 and right cingulate gyrus, and a negative correlation in left BA 6. (7) The results of the correlation between science scores of Basic Competence Test and gray matter density showed positive correlations in left BA 37, left BA 10 and right BA 22, and negative correlations in left inferior occipital gyrus, right inferior parietal lobule, left cingulate gyrus. (8) There existed a negative correlation between EOE and gray matter density in left BA22 and positive correlations between TOE and gray matter density in left BA 22, bilateral BA 40, between SOE and gray matter density in left superior temporal gyrus, and between MOE and gray matter density in right BA 40 and right supramarginal gyrus.