Objective    To evaluate the early changes of right ventricular function before and after adenoidectomy and/or tonsillectomy in children with obstructive sleep apnea-hypopnea syndrome(OSAHS) by quantitative tissue velocity imaging (QTVI), and investigate the influence of OSAHS on right ventricular function and application of QTVI. Methods    20 normal controls and 55 OSAHS children with adenoid and/or tonsil hypertrophy diagnosed by polysomnography (PSG) were enrolled. According to AHI, the patients were further divided into mild， moderate or severe group. Right ventricular function of all subjects were assessed by OTVI. 39 children with moderate to severe OSAHS underwent adenoidectomy and/or tonsillectomy. After 6 months, 25 children received another PSG and QTVI tests. The data was analyzed. Results    Compared with the normal group, systolic peak velocity(Vs) of the tricuspid annulus were decreased in moderate and severe OSAHS (P<0.05), while the early diastolic peak velocity(Ve)、 late diastolic peak velocity(Va) and ratio of Ve/Va were not (P>0.05). In moderate to severe OSAHS, Vs were positively correlated with AHI (R=0.471, P<0.05), but negatively correlated with LSaO2 (R=0.410, P<0.05). 6 months later after adenoidectomy and/or tonsillectomy, the Vs of tricuspid significantly was increased, while AHI was decreased and LSaO2 was obviously increased (P<0.05). But compared with the normal group, no difference was found (P<0.05). Conclusion    It was demonstrated that the right ventricular systolic function of children with moderate to severe OSAHS decreased to varying degrees at early stage. Tricuspid annular velocity detected by QTVI could reflect sensitively the early changes of right ventricular function. Adenoidectomy and/or tonsillectomy were effective methods to treat childhood OSAHS, which could reverse myocardial dysfunction.