In this paper, we discuss autocorrelation properties of a truncated m-sequence which is used in communication and ranging systems based on a Direct-Sequence Spread Spectrum technique such as Tracking and Data Relay Satellite System (TDRSS) of NASA. A truncated m-sequence is obtained by removing a short part or sequential chips from an original m-sequence. We derive methods to calculate periodic and partial autocorrelation functions of a truncated m-sequence with small complexity. Some constraints for truncated m-sequences which originates in system regulation of TDRSS and its related systems are described. In such systems, partial correlation of a truncated m-sequence is important to achieve fast and stable acquisition. We propose some criteria to select a proper set of truncated m-sequence, and derive the set by using the method to simply calculate correlation.