Intellectual disability children due to incomplete or impaired brain development leading to cognitive deficits not only cause problems between communication and learning but also other negative impacts. Although there are many studies on the assessment of children’s balance ability, yet so far there is no proper balance assessment for this underprivileged group. Through this study, the parameters derived from the Force Platform System to understand the similarities and differences between mild intellectual disabilitiy children and healthy children in Sit-to-Stand, as a reference for the establishment of an assessment mechanism. Among the 36 participants, 14 were mild intellectual disability children and 22 were healthy children. On the Force Platform System, the time and the force changes of the Sit-to-Stand are recorded. The results showed that the time factor Lp-seatoff, the value of intellectual disability children is lower than the value of normal children, which may be due to a decrease in the full-time ratio of Sit-to-Stand. According to the weight factor Lpw-seatoffw, the value of intellectual disability children is significantly lower than the value of normal children. The intellectual disability children are more restrictive in their movements and afraid to move which causes the force change in a small weight difference. There will be great contribution to constructing a preliminary balance assessment suitable for intellectual disability children.