 Although psychostimulant is the first line of drug to treat Attention Deficit Hyperactivity Disorder, ADHD, actually there are 10-20 ADHD patient do not response well to current medication. Most of parents of children with ADHD in Taiwan dislike to use psychostimulant. We expect that GlyTI-M will have better efficacy than placebo to reduce ADHD symptoms. This study will also help us to understand the mechanism of ADHD and give a way to develop new drug and also a more possible way to treat ADHD children under 6 years old. 