Abstract: We introduced the baseband loop synchronization design of BD satellite navigation system.We build a model of carrier and code tracking loop system,and analyze the effects of different loop parameters producing on system's performance.Considering of the symbol synchronizating,we adopted Farrow structure to interpolate the data.The simulating results show that the loop parameters do have influence on the rising time and the static error of the tracking loop.The whole tracking loop system can be good at demodulating and de-spreading the original data.