Algorithhm reconstruction is a mathematical procedure used in recontructing images.The characterustics of the CT-Scan image depends on the strength of the selected algorithm. The higher the resolution of the selected algorithm the higher the resolution of the image will be generated. In radiology installation RSUD Tugurejo Semarang on the examination of nasopharyngeal CT-Scan using kernel head parameters.this study aims to determine the difference of anatomical image information and to determine the most optimal kernel value.` This type of research is quantitative research with eksperimental approach. data were collected on 8 patients performing nasopharyngeal examination. then reformat using 4 kernel variations. Respondens as many as 3 people radiologist specialist. Data analysis was done by using kappa test and friedman different test with spss version 16. Result of this research indicate that there are difference of image from four variations kernel with p-value < 0.05. from the average value based on analysis and statistical test, the best image is to use H42S kernel.