Photoplethysmogramm signal is one of the informational signals that deliver the status of the cardiovascular system. Thus in this paper we are interested in locating the various segments and waves helping to extract this information. The work is summarized by a set of algorithms that were developed to identify the peaks and valleys and the period of the signal photoplethysmogrammto measure heart rate, the dicrotic notch locate and assess the variability of the value average of the signal. These properties are of interest diagnosis, for assessing cardiovascular disease in different cases. Thus, these algorithms were tested on a set of signals from different healthy subjects.