Low birthweight (LBW) children tend to have higher risks of developmental problems. According to differential susceptibility hypothesis, these putatively vulnerable children may also disproportionately benefit from positive environmental exposure. This study aimed to examine whether LBW status moderates home environmental influences on preschoolers' motor development in a for-better-and-for-worse manner. Subjects included 18,717 children from the 2005 birth cohort in Taiwan. Birthweight was categorised into: lighter-LBW (LLBW, <2000 g), heavier-LBW (HLBW, 2000-2499 g) and non-LBW (NLBW, ?2500 g) groups. Simple regression slopes indicated that LLBW and HLBW children demonstrated greater susceptibility than NLBW children to the effects of cognitive stimulation component of the home environment on both gross and fine motor skills. Estimating the regions of significance, however, revealed that LLBW and HLBW children appeared more vulnerable to less stimulating conditions, but did not outperform their NLBW counterparts when reared in enriched environments. Thus, our results did not support differential susceptibility.