High precise attitude can be determined using GNSS signal,but the performance of GNSS-based attitude determination algorithm is affected by different signal structures.To deal this problem,first,the relationship between performance of algorithm and accuracy of code and carrier phase is analyzed based on the mathematical model of GNSS-based single frequency single epoch attitude determination algorithm,and then the effects of signal structures on the tracking accuracy of code and carrier phase are studied,finally the key indicator is presented to evaluate the effect of signal structures on the performance of attitude determination algorithm.The simulation results demonstrate that the indicator can evaluate the performance of attitude determination algorithm under different signal structure effectively while the conclusion is important for GNSS signal design and signal selection of receivers.