Abstract: ObjectiveTo observe the characteristic of pulmonary function of children with spastic diplegia and the effects of hydrotherapy on it. Methods30 children with spastic diplegia were divided into hydrotherapy group and control group, who received hydrotherapy and routine rehabilitation or routine rehabilitation only. All patients were tested their pulmonary function and the maximum phonation time before and 2 months after treatment. The longest breath holding time in water of the hydrotherapy group were recorded. ResultsThe vital capacity (VC), expiratory reserve volume (ERV), inspiratory capacity (IC), forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), maximum ventilatory volume (MVV), peak expiratory flow (PEF) in all the children decreased significantly compared with the predicted value (P=0.000), but a second rate (FEV₁/FVC) didn't （P=0.141）. After treatment, the VC, FVC, FEV₁, FEV₁/FVC, MVV, PEF values and their percentage of predicted value improved （P＜0.05）, as well as the maximum phonation time （P＜0.05）. ERV, IC values and their percentage of predicted value improved a little from pre-treatment in the control group （P＞0.05）, but significantly in the hydrotherapy group （P<0.05）. The percentage of predicted value of VC, ERV, IC, FVC, FEV₁, FEV₁/FVC, MVV, and PEF, and the maximum phonation time improved more in the hydrotherapy group than in the control （P＜0.05）. The longest breath holding time in water improved in the hydrotherapy group after treatment （P=0.000）. ConclusionThe pulmonary function impaired in spastic diplegic children, and can be improved with the rehabilitation, especially with the hydrotherapy in addition.

Key words: cerebral palsy, spastic diplegia, pulmonary function, rehabilitation, hydrotherapy, children