Zooplankton is widely distributed in the marine ecosystem,which plays an important role in global climate change.Zooplankton analysis based on image processing needs rapid development.According to the shape of marine zooplankton microscopic image characteristics,a hybrid method based on template matching and invariant central moment description method was proposed in this study.Template matching was used to define the target initial range,and the final target organisms were determined by comparing the moment invariants.The amount and size of the target were calculated.This method was not affected by the rotation of biological azimuth and the scaling of size.The verified experiments show that the proposed method is fast and efficient,which is suitable for situ zooplankton monitoring in real time.