The beta testing is an acceptable testing, which used to evaluate the performance of the medical knowledge-based system. The method of evaluation is comparison between diagnosis of system and a physician. We use simple random technique to select patients from clinic and hospital. The result is shown on table 3. We will see the proposed system has an accurate diagnosis at 98.864% (435 persons from 440 persons) when we compare with a physician. However, we found missing diagnosis at 1.136% (5 persons from 440 persons).