In this paper, we have develope a guidance and control system of a sounding rocket and analized the navigation errors. A proper guidance law for a sounding rocket is studied and the performance of the guidance law is tested by a series of simulation studies. INS technologies needed in the guidance and control system design are also investigated. A series of simulations is carried out for an INS srror analysis and a guidance sensitivity study. Miss distance resulting from various sources at the guidence cut off time is obtained by analyzing sensitivities of the error sources through various simulation runs, and the results verified by simulation.