Pests are organisms that can damage crops in ways that are against the interests and goals of farmers. One of the pests to watch out for is the armyworm (Spodoptera litura) which can cause yield reductions of up to 80%. There are several ways to control pests, one of which is with biological agents. The purpose of this study was to determine the efficacy of Beuveria bassiana, to determine the effect of various application methods and to determine the interaction effect of B. bassiana and various application methods against armyworm (S. Litura) pests. The study used a factorial randomized block design (RAKF), consisting of 8 treatments with 4 replications, namely control, BV Isolat Yogyakarta+Feed, BV Isolat Jember 715+Feed, BV Isolat Jember 725+Feed, control, BV Isolat Yogyakarta +Contact, BV Isolat Jember 715+Contact and BV Isolat Jember 725+. Contact with a dose of 2 g/l (0.2%), 2 g of B. bassiana dissolved in 1 liter of water by squeezing B. bassiana in a filter cloth. The results showed that the biological agent B. bassiana was effective against armyworm (S. litura) with the fastest LT50 value in the treatment of B. bassiana Isolat Yogyakarta+feed method (103 hours). The type of application method of B. bassiana significantly affected the mortality of armyworms, at 168 hours of observation, and had a very significant effect at 120 hours, 144 hours, and 192 hours after application. The interaction between types of B. bassiana and various application methods significantly affected the mortality of armyworm (S. litura) on observation 120 hours after application.