The present study was designed to take advantage of telemetry data acquisition and develop an easy and reliable system to servo-control renal perfusion pressure (RPP). Digitized pressure signals from lower abdominal aorta, reflecting RPP, was obtained by a pressure telemetry device and dynamically exported into an Excel worksheet every 15s. A computer program (LabVIEW) compared the RPP data with a preselected pressure range and drove a bi-directional syringe pump to control the inflation of an inflatable vascular occluder implanted around the aorta above renal arteries. When RPP was higher than the preselected range, the syringe pump inflated the occluder and decreased RPP, and vice versa. If RPP was within the range, there was no action. In this way, the RPP was servo-controlled within desired range no matter what the systemic arterial pressure was. In experiments with norepinephrine- or angiotensin II-induced acute increases in systemic arterial pressure (120-145 mmHg) using Sprague Dawley rats, the system was able to control RPP at a constant range of 100 - 105 mmHg within 30-50 sec. and differentiated the pressure-dependent and -independent effects on renal functions. In Dahl S rats with high salt-induced chronic hypertension, this system maintained RPP at 100 - 120 mmHg over 10 days, while systemic arterial pressures were 150 ± 5.9 mmHg in uncontrolled animals. This system also has ability of simultaneity and multiplexing to control multiple animals concurrently. Our results suggest that this is an easy, effective and reliable system to servo-control RPP in rats, which can be easily established with general computer knowledge using user-friendly LabVIEW software. This system provides a powerful tool and may greatly facilitate the studies in pressure-dependent/-independent effects of a variety of cardiovascular factors.