ObjectiveTo verify the existing domestic and foreign formulas of normal predictive value indicator for adult pulmonary diffusion capacity’s applicability at current stage in Kunming.MethodsBased on the pulmonary diffusion capacity parameters determination of diffusion capacity for carbon monoxide of the lung (DLCO) collected from one-breath breathing test completed by 680 adults with healthy lung function and without any disease which may cause pulmonary diffusion dysfunctions in Kunming, the regression equation of adult DLCO normal predicted value in Kunming was initially established; the fitting degree of DLCO predicted value and measured value was verified; and the correlation between European adults (instrument-inherent ECCS93) and the normal predicted values of adult DLCO in Shanghai, Chongqing and Lhasa were calculated and contrasted.ResultsThe regression equation of adult DLCO normal predicted value in Kunming was initially established: for male, 0.483+0.063×height (cm)+0.041×weight (kg)–0.071×age (years); for female, 1.679+0.055×height (cm)+0.018×weight (kg)–0.060×age (years). The data collected from the one-breath breathing test were similar to the predicted values obtained from the normal adult male and female DLCO prediction formulas in Kunming, the difference was not statistically significant (tM=–0.167, tF=–0.436, both P>0.05), suggesting that the formula for predicting the value established in this study was valid and well fitted. The predicted value of adult DLCO in Kunming area was statistically significant compared with the adult DLCO estimates of European adults and Lhasa, Chongqing and Shanghai in China (FM=713.4, FF=1 442.2, both P<0.001). Lhasa had the highest value; Kunming was the second highest; instrument-inherent European area and Chongqing came to third and fourth; and Shanghai had the lowest predicated adult DLCO value (all P<0.001).ConclusionThe current predictive formulas for adult pulmonary diffusion capacity indicators in China and worldwide are not suitable for the populations in Kunming.