The paper deals with the building of knowledge basis on the existing knowledge amount in a given domain. In our case we operate with new European Hypertension Guidelines, 2003. There are developed two knowledge basis containing one and the same knowledge amount applying different representation techniques, i.e., rules and frames. Those knowledge bases are the central element of the two datorized systems for carrying out decision making on health care strategy of arterial hypertension patients. It makes possible the comparison and estimation of two knowledge basis and datorized systems on the whole. The paper deals with the building of knowledge basis on the existing knowledge amount in a given domain. In our case we operate with new European Hypertension Guidelines, 2003. There are developed two knowledge basis containing one and the same knowledge amount applying different representation techniques, i.e., rules and frames. Those knowledge bases are the central element of the two datorized systems for carrying out decision making on health care strategy of arterial hypertension patients. It makes possible the comparison and estimation of two knowledge basis and datorized systems on the whole. The paper deals with the building of knowledge basis on the existing knowledge amount in a given domain. In our case we operate with new European Hypertension Guidelines, 2003. There are developed two knowledge basis containing one and the same knowledge amount applying different representation techniques, i.e., rules and frames. Those knowledge bases are the central element of the two datorized systems for carrying out decision making on health care strategy of arterial hypertension patients. It makes possible the comparison and estimation of two knowledge basis and datorized systems on the whole.