The P-type perovskite oxides La(1-x)Sr(x)CoO(3) are a promising group of complex oxide thermoelectric (TE) materials. The thermoelectric properties of these oxides are expected to be significantly improved when their critical dimensions are reduced to the nanoscale. In this paper, the La(0.95)Sr(0.05)CoO(3) nanofibers, with diameters in the range of approximately 35 nm, were successfully prepared by the electrospinning process. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize these thermoelectric nanofibers. A micro-electromechanical (MEMS) tester was designed and fabricated to measure the Seebeck coefficient of the nanofibers. The measured voltage output was as large as 1.7 mV and the obtained Seebeck coefficient of the nanofibers reached 650 microV K(-1).