Most of the physiological parameters such as body temperature and blood pressure show circadian rhythms in humans. This evidence is recently supported by the findings that clock oscillation occurs in most of the body cells, which is originally generated by transcription/translation feedback loop of clock genes. Previously, we demonstrated that circadian micturition rhythm in free-moving mice can be monitored by the Automated Voided Stain on Paper (aVSOP) method, which can accurately record the volume of each micturition of mice. In the present study, we improved this system to allow simultaneous recording of micturition and locomotor activity. By improving the machine to be able to record micturition rhythms and behavioral rhythms simultaneously, we examined the wild-type (WT) and clock gene defected (CGD) mice in normal light-dark cycles, and in jet-lag schedule. In normal WT mice housed in 12h-light and 12h-dark (LD) conditions, micturition occurred mostly in night time with the highest amount of void volume just after the beginning of the dark period. When these mice were phase-advanced for 8 hours, day-night variation of micturition was disrupted suddenly, and this irregular daily micturition continued until 8 days, although their behavior rhythms entrained gradually day by day until 8 days. In CGD mice, micturition occurred only in the night time as in WT mice in LD condition. When CGD mice were put in 8h phase-advance jet-lag regime, micturition occurred only in the night as before the time-shift. This daily micturition pattern is consistent with the daily activity rhythm. The rapid change of the micturition and locomotor activity seems to associate with a large and immediate change of clock genes expression in CGD mice upon time-shifting. The increase in micturition after time-shift suggests the inhibitory role of the clock in the daytime in WT mice.