The purposes of this research were to know the influence of concentration of Lantana camara and fermentation length of Bacillus thuringensis to control the nettle caterpillar on palm oil and to determine the most effective Lantana camara concentration and to determine the duration of fermentation. Research with experimental method was condicted in 2 stages. Stage 1 is Bacillus thuringensis and Lantana camara fermentation with factorial experimental method (3x2) arranged in Completely Randomized Design (CRD). Factor 1: Lantana camara concentration, which are (A) 5%, (B) 10%, (C) 15%. Factor 2: fermentation length, which are (P) 3 days, (Q) 6 days. Each treatment was repeated 3 times. Parameters were physical changes during fermentation (color, viscosity, aroma, and pH), and population dynamics and identification of Bacillus thuringensis. Stage 2 Bioassay formula of Bacillus thuringensis and Lantana camara on neetle caterpillar with single factor experimental method and 9 treatment in Completely Randomized Design (CRD), which are namely: (A) Lantana camara 5% 3 daysfermented; (B) Lantana camara 10% 3 daysfermented; (C) Lantana camara 15% 3 daysfermented; (D) Lantana camara 5% 6 daysfermented; (E) Lantana camara 10%6 days fermented; (F) Lantana camara 15% 6 days fermented,with control (G) water, (H) Bacillus thuringiensis, (I) Lantana camara, each treatment repeated 3 times. Observed parameters were weight reduction percentage of caterpillar larvae, mortality rate, and mortality. The results indicated that during the fermentation, which undergoes changes are: odor, color, viscosity, and the pH is neutral. The result showed that the treatment that influenced the caterpillar mortality was with the fermentation formula of Bacillus thuringensis and Lantana camara 10% for 3 days, which the death rate is 4,6 pest/ day and 83% of mortality.