Heart rate variability(HRV) signals can provide the important information about the active state of heart. To set up a reversed sleep model, then, we analyze the 24-hours HRV signals modulated by the reversed sleep state using the power spectrum and base-scale entropy method, and study the effect of the interaction of autonomic nerve system and the chaotic intensity of HRV signals in the case of reversed sleep. Results show that because of the reversed sleep state, the activity rhythm of autonomic nerve is contrary to that in normal state. The variational trend of base-scale entropy is corresponding to that reversed in day and night. This means that the chaotic intensity of HRV signals is closely related to the reaction of autonomic nerve system. In further researches, it is found that the chaotic intensity of HRV signals is in positive correlation with the modulation intensity of sympathetic nerve, but in negative correlation with the modulation intensity of vagus.