Performance / potential matrix (nine-box matrix) has become one of the most popular and yet least understood human resource development intervention in recent years. The major purpose of this study is to examine the effect of job performance and employee potential on promotability evaluations. Drawing on a cross-organizational sample of 430 supervisor-subordinate valid dyads from Taiwan and mainland China, the regression results indicated that although job performance and employee potential were positively correlated with promotability evaluations, employee potential had stronger effects on promotability evaluations than job performance. Implications for management theory and practice are discussed.