The previous native-state hydrogen exchange experiment with barnase failed to detect anypartially unfolded intermediate state which was contrary to the experimental results from kinetic deuteriumhydrogen exchange pulse labeling and protein engineering studies. This has been taken to suggest thatthe native-state hydrogen exchange method cannot be used alone as an analytical tool to study the foldingpathways of proteins. Here, we revisited the pulse labeling experiment with barnase and detected nostable folding intermediate. This finding allows a reconciliation of the native-state HX data and the foldingpathway of barnase. Along with alternative theoretical interpretations for a curved chevron plot of proteinfolding, these data suggest that further investigation of the nature of the intermediate of barnase is needed.