Provided are a capsule endoscopic receiving device, a capsule endoscope system including the same, and an operating method of the capsule endoscopic receiving device, the capsule endoscopic receiving device including an analog front end configured to receive a preamble from one receiving electrode pair from among a plurality of receiving electrodes, a valid signal detection circuit configured to compare a reference voltage with input data generated on a basis of a voltage level of the preamble, and a preamble processor configured to select a final electrode pair configured to receive the image data on a basis of a correlation value of the preamble and a comparison result of the input data and the reference voltage. According to the inventive concept, stability of receiving image data may be secured by selecting an optimal receiving electrode pair.