The aim of study was to analyze the fertilization rate of Lukas fish (Puntius bramoides) after stimulated by GnRH analogue. Milt and eggs were collected by hand stripping method. Milt was then diluted with physiological NaCl 0.9%. The ratio of milt and diluents was 1:9. The experimental treatment consisted of four groups, such as: A (normal/control, without dilution), B (10 times dilution), C (100 times dilution), and D (1000 times dilution). Eggs were then fertilized manually, and were calculated the percentage of fertility and hatching rate. The result showed that the highest percentage of fertility and hatching rate at 1000 times dilution (78,92 ± 1,81) % and (72,33 ± 4,56) %, respectively. Anova test expresses the optimum fertility and hatching rate showed significant differences at 1000 times dilution (p<0,05). Water quality parameters observed in the study were water temperature of 23°C - 24°C and pH 5 - 6.