OBJECTIVE Exercise induced oscillatory ventilation (EIOB) during cardiopulmonary exercise testing (CPET) is associated with severity and prognosis of disease, but clinical approach for the character of EIOB due to circulatory dysfunction are seldom reported. METHODS This retrospective analysis of symptom-limited maximum CPET data with an increment of 10-20 W/min in 38 patients with CHF. We calculated the duration, frequency, amplitude and other parameters of EIOB. RESULTS There were 31 presenting with EIOB (82%) in all patients with CHF. In EIOB group, VE amplitude were (12.4 ± 4.4)L/min (accounting for 81% ± 30% of mean) and duration were (77.0 ± 20.0)s. The number of patients whose EIOB presenting at rest, exercise, recovery stage and the whole eriod were 24, 31, 4 and 4, respectively. Except VE, there were VO2, VCO2, RER and PETO2 presenting EIOB in all 31 patients; VE/VCO2, VO2/VE and breath frequency in 29 patients; PETCO2 in 26 patients; VT and VO2/HR in 25 patients; and HR in 2 patients. CONCLUSIONS EIOB may occur in any period of CPET, mostly in severe patient with CHF, and presenting in many variables. Due to it is resulted from the circulatory dysfunction, we should call it circulatory (cardiac) oscillatory breathing abnormality.