Background and objectives: Brachial-ankle pulse wave velocity(baPWV) is widely used as a simple and noninvasive measuring method of arterial stiffness. But the reproducibility in an individual is relatively poor because it is sensitive to the acute changes of blood pressure(BP). The aim of this study is to define clinical parameters of responsiveness of baPWV to acute BP changes. Subjective and Methods: We defined a parameter for responsiveness of baPWV to acute BP changes as ��baPWV/��mean BP when ��mean BP > 5mmHg. Among 70 patients recruited for the ��baPWV study, 18 patients whose ��mean BP were below 5mmHg were excluded. We analyzed clinical parameters related to the responsiveness of baPWV to acute BP changes. Result: Mean age was 60.1짹8.9 yr. Male patients were 67%. Multiple linear regression analysis showed only creatinine level and age are independent factors to determine the responsiveness of baPWV to acute blood pressure changes. Conclusion: These results suggest that in elderly patients and/or in patients with renal insufficiency, baPWV might have a greater tendency to decrease in response to a lesser decrease in BP and that the volume status may be involved in the responsiveness of baPWV to acute BP changes.