Objective: To investigate the effects of skeletal Class III malocclusion(SCIIIM) on speech articulation in the children with mixed dentition.Methods: 38 children aged 7.5～11.5 years old with skeletal Class Ⅲ malocclusion and mixed dentition were selected in a SCIIIM group, other 40 children at similar mean age with normal occlusion were selected in a control group.The articulations of the children were examined by phoneticians and the discorded speech sounds were analysed by computerized speech lab. Results: Misarticulation(%) of z,c,s,zh,ch and sh in SCIIIM group were 27.4,46.3,34.7,6.3,9.5 and 6.8 respectively. The voice onset time(VOT) of resonant note and resonant fricative note in SCIIIM group was nought while that in the control group was positive. Conclusion: There is articulatory misfunction in most Class III malocclusion patients with mixed dentition.