BACKGROUND: In clinical practice, the degree of cognitive competence damage correlates to fine motor function deficits in children with psychomotor development retardation. Clear correlations between the two can help to develop and perform corresponding functional training for children with mental retardation (MR). OBJECTIVE: This study was designed to evaluate and analyze the correlation of fine motor function to cognitive competence in MR children using the Peabody Developmental Motor Scale-Fine Motor (PDMS-FM) and Symbolic Play Test. DESIGN: Scale evaluation and correlation analysis. SETTING: Childrens Rehabilitation Center & Huajing District Hospital, Childrens Hospital Affiliated to FudanUniversity.PARTICIPANTS: A total of 42 MR children, 28 males and 14 females, aged 14-69 months, were admitted to the Rehabilitation Center, Childrens Hospital, Fudan University between June 2003 and April 2006, and were recruited for this study. All children corresponded to MR diagnosis criteria determined by Chinese Neurology and Psychiatry Society in 1989. Written informed consent for participating in the evaluation and for evaluated content was obtained from each childs guardian. METHODS: Subsequent to admission and prior to treatment, fine motor function of each MR child was evaluated using PDMS-FM (Chinese version). The scale captured 98 items that formed the grasping (Gr) and visual-motor integration (Vi) subtests. Cognitive competence was evaluated using the Symbolic Play Test (Chinese version), which captured four 6-item specific contents. The original score of each subtest was used to evaluate results for statistical analysis. Higher scores from the two evaluations indicated stronger abilities. Pearson correlation analysis was applied for analyzing data correlation. MAIN OUTCOME MEASURES: Fine motor function was evaluated using PDMS-FM. Cognitive competence was measured using the Symbolic Play Test. Correlations between results from the two evaluations were analyzed. RESULTS: All 42 MR children were included in the final analysis. Correlation analysis results demonstrated significant positive correlations of original scores existed between Gr and Vi subtests in the PDMS-FM (r = 0.761, P < 0.01), and between Vi and Gr subtests in PDMS-FM and Symbolic Play Test (r = 0.663, 0.450, P < 0.01). CONCLUSION: Fine motor function closely correlates to cognitive competence in MR children. This indicates fine motor function training should be developed in combination with cognitive competence training.