Helicoverpa armigera (Hubner) is an important pest of corn crops. Lecanicillium sp. and Helicoverpa armigera Nucleopolyhedro virus (HearNPV) are biological control agents that are safe for the environment. This study observed pathogenicity of HearNPV and Lecanicillium sp. against eggs and larvae H. armigera. The results showed that HearNPV application was not able to infect eggs, but the mortality effects of newly hatched larvae and second instars larvae at density of 107 was 100% and 90% respectively, while in mixed applications Lecanicillium sp. and HearNPV on eggs at 107 caused 17.5%, and eventually died were 100%. At 107 concentration with mixure of application (Lecanicillium sp. and HearNPV) mortality was only 26.25%. The value of LT50 in HearNPV application against H. armigera larvae was 2.03 days faster than that of mixed applications on 3.23 days. A conclusion statement HearNPV was more effective against H. armigera than mixed application (HearNPV and Lecanicillium sp.)