The research on the effect of forages energy level on production and reproduction performances of Kosta female goat was conducted in two phases. The first phase, was observing the growth of Kosta female goat starting from the weaning age of 4 months to first puberty at 7 months and then to mating at 9 months. The variables found at this stage were: daily weight gain, the rations consumed, and the puberty age of the herd. The second phase was observing Kosta female goat from mating until giving birth. The variables determined were: ration consumed, body weight gain, length of pregnancy, litter size, birth weight and weaning weight. The research was conducted in experimental methods by using 24 four months old Kosta female goats weighing 6-7kg, and 3 ram aged at 3-4 years. The design of the experiment used was completely randomized design. The treatments were 3 levels of ration energy 53% TDN (R1), 61% TDN (R2) and 69% TDN (R3), with relatively equal protein percentage of 12% (isoprotein). Each treatment was replicated 8 times. The rations were forage consisted of field grass, leaves of: waru (Hibiscus tiliaceum. L), lamtoro (Leucaena glauca), gamal (Gliricida septium), and jackfruit (Artocarpus heterophylla). Generally, result of this experiment indicated that: (1) the higher the dietary energy up to 61% TDN in the ration, the higher the production performances of Kosta female goats in term of efficiency of ration usage, body weight gain, birth weight, and weaning weight; (2) the higher the dietary energy up to 61% TDN in the ration, the higher the reproduction performances of Kosta female goats in term of age of puberty, length of pregnancy, and litter size.