The microflow in the bronchial mucosa was measured by means of electrochemically generated hydrogen on dogs, identifying close producibility of measurement. In general anesthsia, the microflow of tracheal bifurcation was 71.5± 13.23ml/min/100g that of right main bronchus, 65.6±10.84 and that of left main bronchus, 69.0±12.51 respectively. There was no significant difference in microflow between anastomically difeerent sites. Basic diffusion in the bronchial mucosa was estimated as many as 17.0±4.80ml/min/100g. The microflow at bronchial anastomosis in autografts increased on day 3 and hyperdynamic state continued on day 7 to 14. On the other hand, that in allografts treated with cyclosporine A (CyA ) showed increased levels on day 5 although that treated with azathioprine demonstrated lower levels until on day 7, thereafter increased on day 10
