The study aimed to determine the effect of N-Hexane extract of Andrographis paniculata leaves on testis weight of male mice (Mus musculus), along with the amount, motility, viability, and abnormality of its sperm. The tested animals used in this study were male Mus musculus aged 10-12 weeks with the average body weight (bw) of 21 g. The study was an experimental study with a Completely Randomized Design (CRD), which consists of one control group (A0, without extract) and three experimental groups (A1, A2, A3, with the extract concentration of 125 mg/kg bw, 250 mg/kg bw, and 500 mg/kg bw, respectively). The volume of extract given to each experimental mice was 1 cc per day, for a total of 18 days. The parameter of observation were the weight of testis, along with the amount, motility, viability, and the total of abnormal sperm. The data collected were analyzed by using F Test (α 0,05) and BNT Test (α 0,05). The result of data analysis showed that the N-Hexane extract of A. paniculata which was given for 18 days consecutively has affected the spermatozoa production of male mice. Each concentration of N-Hexane extract of A. paniculata (125, 250, and 500 mg/kg bw) had caused the decreasing of testis weight; the decreasing of spermatozoa production; the decreasing of motility and viability of spermatozoa; and the increasing of abnormal sperm. Hence, the study suggested that the N-hexane extract of A. paniculata has the potential to be used as antifertility treatment as it decreased the reproductive fuction of male Mus musculus. The extract concentration which cause the biggest effect is 500 mg/kg bw.