The properties of electrical resistance of Mn-Co-Ni-Fe oxide-based thermistor with various Fe contents in sintering process at $1200^{circ}$ to $1400^{circ}C$ for 4 hours in air atmosphere for fabricating thermistor materials were investigated. The results were as follows: all samples showed single cubic spinel crystal structures in all region. The electrical conductivity is the highest thermistor sintered at $1300^{circ}C$ for 4 hours. In general when the Fe content is increased except F-2, the resistivity increases and relatively the conductivity decreases. Particularly F-2 composition exhibited the highest electrical conductivity (1.4${ imes}$$10^-3$${ extohm}cm) and relatively low B constant(2906K)