Purpose: The results of pulmonary function test (PFT) in children are variable according to the patient's cooperation and comprehensiveness. This study has intended to figure out the effectiveness of pre-education and training with balloons on PFT in children. Methods: One hundred six children mean aged 9.35+/-2.92 years were tested. All participants performed PFT twice in 30 minutes intervals. First PFT were performed after usual instruction and second PFT were performed according to randomly classified grouping; Group 1 : repeat PFT after training with balloons, Group 2 : repeat PFT after training and education, both, Group 3 : repeat PFT after education about objects and necessities of pulmonary function test, Group 4 : repeat PFT without any education and training. Results: There were no difference statistically on the results of percent of predicted FEV(1), FEV(1)/FVC, FEF(25-75%) and PEFR in Group 1, 2 and 4 patients. In some cases, the average is decreased with repeated PFT. At the case of repeated PFT after education, the average of percent of predicted FEV(1), FEV(1)/FVC, FEF(25-75%) and PEFR is increased. There was statistically significant difference on the value of FEV(1), FEF(25-75%) and PEFR between first and second PFT in Group 3. Conclusion: Training with balloons before PFT causes fatigueness and lowers concentration. Understanding of PFT makes results better than training. Therefore, enough explanation and education about PFT before examination is most effective for appropriate PFT in children.