The periodontal probe is a commonly used instrument to assess periodontal conditions. And so, there has been many studies to develop the accuracy and reproducibility of the periodontal probe. The purpose of this study was to compare two different periodontal probes for measurement reliability and time required to use in subjects with moderate periodontitis. It was done after evaluating reproducibility of probing depth by stent guiding for a Manual probe and a Florida probe in subjects with healthy periodontal condition. The results were as follows : 1. In experiment to evaluate the reproducibility of probing depth by stent guiding for a Manual probe and Florida probe in subjects with healthy periodontal condition, there was no major significant difference between intraprobe and interprobe relationships. 2. There were reduced probing measuremint error by using the Florida probe for posterior teeth and by using the Manual probe for anterior teeth of subjects with moderate periodontitis. 3. At proximal area, there was higher measurement error by using the Manual probe than the Florida probe. 4. The mean of pocket depth measurement using Manual probe was signifi cantly higher than that using Florida probe(p<0.05). With increasing pocket depth, interprobe difference increased and reproducibility reduced. 5. There was no significant difference in time required to use between Manual probe and Florida probe(p<0.05). 6. There was slight probing measurement difference between Manual probe and Florida probe at different site, but both probes have similar degrees of reproducibility and similar time required to probe.