Objective: To examine the developmental trajectory of fine motor ability in schoolage children with attention deficit hyperactivity disorder (ADHD) for two years, so as to provide scientific evidence to promote motor development in ADHD children. Methods: From April to June 2019, 31 children aged 6-8 years old were selected from a public elementary school. They were diagnosed with ADHD by two psychiatric professionals according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) criteria. Additionally, 31 typical developmental children, matched for age, sex and IQ with the ADHD group, were recruited as the control group. Fine motor ability was assessed with tasks of hand manual dexterity in Movement Assessment Battery for Children-2 (MACB-2), and a followup assessment was conducted from April to June 2021. The development changes of fine motor ability between two groups of children were compared by using t test and repeated measures analysis of variance. Results: Between baseline and followup periods after two years, the total score of hand fine motor in the ADHD group did not show significant improvement (7.4±3.0, 8.0±3.4; t=-1.05, P>0.05), while there was a small effect size improvement in typically developing control group (9.5±2.1, 10.5±2.4; t=-2.12, effect size=0.38, P<0.05). Followup after two years, coin/peg throwing scores with dominant hand improved between ADHD group and control group (7.0±3.3, 9.5±3.2; 8.4±2.8, 11.6±1.6) (t=-3.74, -6.33, P<0.01; effect size=0.67, 1.14), with a smaller improvement in the ADHD group. The score for threading beads/threads decreased in between ADHD group and control group (7.9±2.4, 5.8±3.1; 9.2±1.1, 8.2±1.9) (t=3.89, 2.78, P<0.01; effect size=0.70, 0.50), with a greater decrease in the ADHD group. Conclusions The development speed of fine motor ability in children with ADHD aged 6-8 is slow and continues to lag behind normal developmental children. Fine motor development in children with ADHD should be closely monitored, and targeted interventions should be implemented when necessary.