The present invention is an apparatus and method for detecting the motion characteristics of particles in a flow channel. The apparatus includes first and second electrode groups, each having a pair of electrodes, which are arranged to be spaced apart from each other in a flow channel. The pair of electrodes function as both a drive electrode and a sensing electrode for directly applying voltage and measuring impedance between the electrodes. An operation control unit measures variation in electrical pulses generated in the first and second electrode groups, thus detecting motion characteristics of the particles. The present invention is advantageous in that it does not require complicated optical measuring instruments or analyzing instruments, and in that it can be used to easily detect the motion characteristics of particles in a flow channel merely by analyzing variation in electrical pulses without requiring preliminary information.