RESUMO
<p><b>OBJECTIVE</b>To explore the time law of electroacupuncture in regulation of circadian rhythms of the organism.</p><p><b>METHODS</b>Effects of electroacupuncture at "Shenshu" (BL 23) at Zi, Wu, Mao and You periods on circadian rhythms of locomotor activity and core body temperature in hamsters were observed with chronobiological research methods.</p><p><b>RESULTS</b>Electroacupuncture at Wu period could decrease the amplitude of locomotor activity rhythm (P < 0.05), at Mao period could delay the peak phase of circadian rhythm and at You period could advance the peak phase of circadian rhythm (both P < 0.05); and electroacupuncture at Mao period could delay 22.36 degrees and at You period advance 39.32 degrees for the rhythm peak of the circadian rhythm of core body temperature.</p><p><b>CONCLUSION</b>Acupuncture has a certain effect on circadian rhythm of locomotor activity and core body temperature.</p>