When designing an optical communication system it's necessary to know amount of the chromatic dispersion. This is important because of the possibility for chromatic dispersion compensation or for knowing when dispersion reaches the ultimate limit in terms of information capacity and limit on distance between signal repeaters on optical link. Chromatic dispersion is the primary reason for the intersymbol interference in singlemode optical fibers. In this teasis has been analysed system for measuring of chromatic dispersion in single-mode optical fibers using the phase method. By now it has been developed and successfully used many techniques for chromatic dispersion measurement, but many of them were not ideal because of hard adaptation in industry or on the field, and they were not very cost efficient. The phase method uses an optical signal which is obtained by laser diodes modulated with high frequency oscillating signal. It's possible to obtain all the information about the chromatic dispersion of the single-mode optical fiber with simple conventional optical and electronic circuitry. In scientific papers has been proved to be a good technique with satisfactory accuracy, an appropriate resolution, ease of development and relatively low cost. The time delays that are used for better understanding of phase comparator system design has been measured. Techniques for approximations of time delays with Sellmeier equations were used. Phase comparator which multiplies digitized reference and test signal and from the temporal width of the resulting impulse gets the amount of phase delay has been designed. From phase delay is readily determined the chromatic dispersion parameter.