Abstract: In the autom atic hom ing phase ofautom ated rendezvous and docking, theaccuracy of Hillguidance is concerned w ith severalerror factors. The error factors consid ered here are navigation and actuation errors. Basic analytic form ulas correlating targetingerror to navigation error and actuation error are given. Based on the form ulas, how to de sign a rendezvous trajectory to reduce the influence ofthe error factors on term inaltarget ing accuracy is studied. Fora typical V bar approaching path, sim ulation results are pre sented. The results in this paper also suit R bar approaching path.