Abstract. Preterm infants are susceptible to opportunistic infection because of their immature immune system. With regard to fungal infection, Aspergillosis is second only to Candida infection in these patients. Here we report the case of an extremely low birth weight (ELBW) infant who developed pulmonary Aspergillosis and was successfully treated by micafungin (echinocandins). The infection occurred in the cavity in chronic lung disease and was diagnosed by typical CT imaging and detection of Aspergillus galactmannan antigen in the serum specimen. To our knowledge, this is the first report of pulmonary Aspergillosis treated with micafungin in ELBW infants.