The final goal of our research is to develop a rehabilitation support robot for self-standing-up training of hemiplegic stroke patients to restore normal standing-up motion. To improve the motor function of the patient's paralyzed leg, a guided standing-up training is effective. The therapist controls the patient's left/right load balance by pulling or pushing the patient's waist during standing-up training. The purpose of this study was to clarify the patient's waist movement guided by the therapist during the guided standing-up motion. For this purpose, we investigated the relationship between the patient's waist movement and the left/right load balance during guided standing-up motion. From the analysis results, we found the ideal pattern of load balance ratio during guided standing-up training. Moreover, we found that the patient's waist movement corresponded to the ideal pattern of load balance ratio. This movement trajectory is expected to be useful in designing a controller of a rehabilitation support robot.