Objective To investigate the curative effect of Sandplay therapy on attention deficit hyperactivity disorder (ADHD)preschool children co-morbid sleep disorder. Methods According to the random number generated by EXCEL software′s RAND function, a total of 62 ADHD children co-morbid sleep disorder were randomly divi-ded into experimental group(n=31)and control group (n=31). The control group was treated with family behavior therapy and the experimental group was treated with sandplay therapy based on the family behavior therapy.With the Achenbach Child Behavior Check List (CBCL), Conners Parent Symptom Questionnaire (PSQ), Conner Concise Questionnaire (Conners Abbreviated Symptom Questionnaire, ASQ)and Children′s Sleep Habit Questionnaire(CSHQ), the overall curative effect was evaluated before and after treatment by their scores. Results The results of independent-samples t test showed that the scores of PSQ′s all factors, ASQ′s and CBCL′s total score, CSHQ′s total score and all factors had no significant difference between the two groups before the intervention(tconduct problem=-0.847, tlearning problems=0.504, tpsychosomatic disorder=-1.008, thyperactivity/ impulsion=-0.331, tanxiety=0.690, thyperactivity index=0.757, tCBCL′s total score=-0.532, tASQ′s total score=0.514, tCSHQ′s total score=1.132, tsleep impedance=-0.767, tsleep latency=-0.634, tsleep duration=0.150, tsleep anxiety=0.149, tsleep wake=0.417, tsleep disorder=0.709, tsleep apnea=0.950, tdaytime sleepiness=1.530, all P>0.05). The scores of PSQ′s all factors, ASQ′s and CBCL′s total score, sleep impedance, sleep latency, sleep duration, sleep wake, daytime sleepiness and CSHQ′s total score all had significant differences between the two groups after the intervention(tconduct problem=-3.982, tlearning problems=-2.258, tpsychosomatic disorder=-2.470, thyperactivity/ impulsion=-4.377, tanxiety=-2.684, thyperactivity index=-4.249, tCBCL′s total score=-3.982, tASQ′s total score=-5.576, tsleep impedance=-3.712, tsleep latency=-2.947, tsleep duration=-2.332, tsleep wake=-6.031, tdaytime sleepiness=-6.256, tCSHQ′s total score=-6.706, all P<0.05). The results of analysis of variance of repeated measurement showed that PSQ behaviour problem, psychosomatic disorder, hyperactivity and hyperactivity index scores of the main effects of intervention had significant difference (Fconduct problem=4.966, Fpsychosomatic disorder=5.176, Fhyperactivity/ impulsion=4.949, Fhyperactivity index=4.926, all P<0.05); the main intervention effects of ASQ and CBCL′s total score had statistical difference (FCBCL=4.398, FASQ=4.814, all P<0.05); the main intervention effects of sleep impedance, sleep duration, sleep wake and CSHQ′s total score had statistical difference (Fsleep impedance=5.697, Fsleep duration=4.467, Fsleep wake=6.610, FCSHQ′s total score=6.016, all P<0.05). There were significant differences in the characteristics of the initial sand table and the final sand table in the experimental group [traumatic subject: (4.48±1.55)cases vs.(1.23±0.81)cases, t=8.247; curing subject: (1.77±1.09)cases vs.(4.55±1.46)cases, t=11.274, all P<0.05]. Conclusion Sandplay therapy can effectively improve the core symptoms of preschool ADHD children co-morbid sleep disorders, which can be used as an early intervention. Key words: Sandplay therapy; Attention deficit hyperactivity disorder; Sleep disorder; Preschool children; Psychological treatment