Abstract: Objective To establish the predicted value of lung function determined by impulse oscillometry (IOS) in children ( 5 ~ 11 years old) in Shanghai. Methods A total of 746 healthy children aged 5 to 11 in Shanghai were included. The Master Screen IOS pulmonary function device (Jaeger Co, Germany) was used to detect the respiratory total impedance (Zrs) , response frequency (Fres), viscosity resistance ( Rrs ) and elastic resistance (Xrs) at various oscillation frequencies, and the indexes above were analyzed. The stepwise multivariate regression was used to establish the regression equation of related parameters of IOS in different genders. Results The median age of 746 children ( 510 boys and 236 girls) was 8 years, ranging from 5 to 11 years. The height of male in 5 -year-old group was higher than that of female, and the weight of male in 5 -, 7 - and 10 -year-old group was higher than that of female, and the differences were statistically significant (P< 0 . 05 ). The differences in the main IOS parameters between different age and height groups are statistically significant regardless of sex (P< 0 . 05 ). The values of Zrs, Fres, R5 and R20 decreased with the increase of age and height, while X5 increased with the increase of age and height. The stepwise multivariate regression analysis showed that IOS parameters were related to height, age and weight, and most IOS parameters were most closely related to height (the absolute value of regression coefficient was the largest). Conclusions The study revealed the normal predicted value of pulmonary function by IOS in healthy children in Shanghai. In the evaluation of the results of the lung function measurements, the use of this predicted value equation is more in line with the characteristics of Chinese children than that of foreign countries.

Key words: impulse oscillometry; respiratory function test; normal predicted value; child