The present study had two aims: First, to investigate the joint and specific roles of working 17 memory (WM) and intelligence as predictors of school achievement. And second, to replicate 18 and extend earlier findings (Spinath, Spinath, Harlaar, & Plomin, 2006) on the incremental 19 validity of non-cognitive over cognitive abilities in the prediction of school achievement. The 20 present sample consisted of N=179 Chinese primary school children in the fourth grade. All 21 measures including working memory (WM), intelligence and motivational items were 22 assessed in class. Teachers provided test scores for the domains of Chinese and Math. We 23 found that WM was a good predictor of school achievement and comparable in predictive 24 power to intelligence. Together, cognitive ability including bothWMand intelligence explained 25 17.8% and 36.4% of the variance in children's Chinese and Math scores, respectively. The relative 26 importance of WMand intelligence varied with school domains with greater predictive power 27 of WM for Math while intelligence explained a greater proportion of the variance in Chinese 28 although the magnitude of this difference was only moderate. Domain-specific motivational 29 constructs contributed only marginally to the prediction of school achievement for both 30 Chinese and Math.