High—Resolution Observation and Analysis of the H-alpha Profile of HR1099

HR 1099 is a RS CVn system with high chromospheric activity. Its H-alpha line has an over continuous level emission, and the emission profile changes greatly with the orbital phase and activities in the chromosphere. Based on the observations obtained in Yunnan Observatory and McDonald Observatory in 1990 and 1984, raspectively, we give our explanation on the varing profile as follows: 1) The H-alpha emission mainly emits from the cooler component, the main one. 2) The mechanisms of the H-alpha emission formation are the photoionization and collision exitation. 3) The dips on the emission profile are mainly due to movements of the chromospheric matter and cool plasma cloud caused by large starspots.