The  goal of this study to use carotid ultrasonography to detect changes in carotid  flow time in comparison to echocardiography in assessment of changes in heart dynamics to assess changes in volume status before &after passive leg raising  in septic patients. We arranged patients into two groups ,Group one: fluid responder 18 paients (45.5%), Group two non-fluid responder :22 patients(54,5%) . Increase carotid flow time (CFT) by 7msec is cosidered fluid responsive, 10% increase in stroke volume to be fluid. The PLR test could assess fluid responsiveness with specificity 100% and sensitivity 95% with cut of 10.6% change in CO to predict fluid responsiveness.the study show a statistically significant moderate positive correlation between CCA  flow time (CFT) both after PLR and the percent of change in CO measured by echocardiography. An agreement analyses were formed, we concluded that an overall good agreement between carotid artery blood flow measurement and Doppler echocardiography measurement with P value < 0.001, so we can use this parameters to predict fluid responsiveness post PLR perform are promising tool for the evaluation of fluid responsiveness in critically ill septic patients ,The PLR maneuver has demonstrated excellent performance for predicting fluid responsiveness. It is simple to perform, but requires a reliable system of COP monitoring able to quantify the short-term changes.