In intracavitary therapy, particular attention is paid for precise determination of the doses to be applied.For dose calculation in intracavitary therapy, longitudinal and transverse distance from the center of sources tocertain points should be detemined. They are obtainable from the knowledge of the position and direction of thesourses. Because the images of sources, in particular, in ovid couldn't be seen, it is not easy to decide theposition and direction of sources, and size of images. A simple method determining the actual position anddirection of the sources in three dimensional space is presented. Also all parameters essential to ensuringsatisfactory simulation is described.