The purpose of this study was to determine potential meniran (Phyllanthus niruri Linn) extract nano herbal as immunomodulator and phytogenic feed additive for natural growth supporter on spleenic germinal centre and performance of broiler chickens. The study started by conducting feed adaptation that was carried out when chickens aged 14 days to 21 days old by giving meniran (Phyllanthus niruri Linn) extract nano herbal to the treatment groups in stages as much as 250g, 500g to 1kg in 1 ton of feed. The treatment groups were then given meniran (Phyllanthus niruri Linn) extract nano herbal in concentrations 5% (T1), 10% (T2) and 20% (T3) through feed with a ratio of 1kg of meniran extract nano herbal: 1 ton of feed starting from chickens at 21 days to 35 days old. Histopathological examination of the spleen was carried out 5 fields of view each and observed in the form of the diameter of germinal center of spleenic white pulp with a magnification of 100X using a Nikon Eclipse microscope.Data that collected during treatment were feed consumption, body weight gain, feed conversion ratio and performance index. Data were analyzed by analysis of variance and Duncan's test. The results showed that meniran (Phyllanthus niruri Linn) nano herbal extract concentration of 5% resulted in the best performance. It showed higest splenic germinal centre,feed consumption, body weight, performance Indonesia and also lowest feed conversion ratio. In sum, we conclude that meniran (Phyllanthus niruri Linn) extract nano herbal as immunomodulator can increase immune system in broilers chicken