This study presents a multichannel oscillatory-flow micro-fluidic chip for high-throughput polymerase chain reaction (PCR). The micro-fluidic chip consists of microheaters and temperature sensors integrated on silicon substrates and parallel microchannels fabricated with glass/PDMS laminates. In order to achieve multiplex thermal protocols simultaneously, the micro-fluidic chip combines uniform resistors and gradually changed resistors on the heater chips. By regulating the heating power of the gradually changed resistors, a controllable temperature gradient was obtained on the micro-fluidic chip for same/different annealing temperature. Then the temperature gradient was investigated in the experiment. The results showed that the temperature difference could change from 0 to 20 °C in the range of about 50---70 °C with low power consumption. Finally, the performance of the developed micro-fluidic chip was successfully demonstrated by amplifying a detection gene associated with hepatitis B virus (HBV) at same and different annealing temperature, respectively. The developed micro-fluidic chip may provide a useful platform for high-throughput PCR amplification.