The electro-spinning is a process in which a jet is ejected by the electrical force which is acting on the droplet and overcoming its surface tension. Unstable jet is ejected under the condition named as Fluctuation that is defined as jet instability. In this study, the dynamic behaviors of a pendant droplet at the exit of the nozzle were investigated to understand the key parameters in the jet instability. The system was developed to control the flow rate of a pendent droplet. Dynamic behaviors of a droplet in electrospinning with the various needle diameters, TCDs (tip-to-collect distance), voltages could be successfully classified into particular steps. Various behaviors of the droplet in electrospinning that may influence the jet instability were investigated.