Composite fibers consisting of poly(methyl methacrylate)-polyethyleneimine (PMMA-PEI) core-shell particles embedded in polyvinylpyrrolidone (PVP) were successfully fabricated by the electrospinning method. The electrospun fibers were produced using 18 % w/v aqueous PVP solution blended with 2 % w/v PMMA-PEI particles at various pH (1, 2, 3, and 4) with a fiber collection distance set at 10 cm. The applied electrical voltages (10, 12, 14, and 16 kV) significantly affected the morphology and diameter of the prepared composite fibers (141-353 nm). The smallest composite fibers were obtained from the spinning mixture at pH 2 and a voltage of 14 kV. The composite fibers would potentially be applied as drug and bioactive compound carriers.