Traditional medicine substances which come from plants have been used by society since long time ago. One of them which usually used is Sambiloto plant. Even though sambiloto has numerous of benefits but utilizing of this substance is still inappropriate dose. This case is anxious that it will bring about harmfulness, if it is consummated in numerous doses, especially for woman who having a pregnancy. Its causes are as anti-fertile and abortifasien. Based on the case above, researcher studied to find out the effect extract sambiloto toward mouses reproduction cycle. This Research is experimental research where used RAL design, 4 treatments and 6 repeating. Extract of sambiloto was given to mouse by gavage while 25 days (5 normal cycle). Extract was given by doses 2 mg/kgbb, 4 mg/kgbb, and 6 mg/kgbb. Observation of estrus cycle length was be done by constructing of apusan vagina. The data which was collected was analyzed by (ANOVA) significance grade 0, 05 and it was continued by Duncan New Multiple Range Test (DNMRT). The finding showed that there was transformation toward estrus cycle length. In group control ( 0 mg/kgbb ) has significant effect, if it is compared by experiments group; 2 mg/kgbb(P1), 4 mg/kgbb(P2), 6 mg/kgbb(P3). The researchs result also showed that using extract of sambiloto could be an herbal contraceptive. Thus, it was conclude extract sambiloto by doses 2 mg/kgbb(P1), 4 mg/kgbb(P2), and 6 mg/kgbb(P3) give significant effect to lengthen mouses estrus cycle.