Nanofiber technology has played an important role in recent material research studies. Electrospinning is an elegant and simple method for nanofiber production, which allows the fabrication of ultrathin non‐woven of given polymer fibers directly from its solution in the presence of an electric field. These nanofiber mats have distinct advantages such as an extremely high surface area to volume ratio and porosity, both of which, are desirable properties in advanced applications. Graphene, a new carbon material with two-dimensional (2D) nanostructure, has been extensively studied owing to its exceptional chemical and excellent electronic properties, optimal mechanical stiffness, and electrical conductivity. These unique features have led to the use of graphene in a wide area of applications such as sensors, flexible electronics, etc.. Polyaniline (PANI) on the other hand has potential utility in synthesizing conducting graphene/polymer due to its reversible control of conductivity by charge-transfer doping and protonation, good processability, and environmental stability. Therefore, it is expected that the functionalized graphene /PANI nanofibers composite can enhance the sensitivity and selectivity of the sensor, through the combination of excellent sensing materials. In this work, amine-functionalized graphene (AmG)/PANI were in situ, polymerizated at the surface of electrospun poly(methyl methacrylate) (PMMA) nanofibers to obtain flexible, composite nanofibers for gas detection. The surface of the PMMA nanofibers was treated at room temperature by ultraviolet (UV) radiation. The observations showed that the UV radiation reduced the hydrophobicity of PMMA surface by introducing oxidized groups onto the nanofiber surface. The morphology and microstructure of the nanofibers were characterized by scanning electron microscopy (SEM) and the electrical conductivity of the nanofibers at room temperature was investigated by the four point probe method.