An embodiment of the invention discloses a tracking method, a track detection processing unit and a monitor system. The tracking method comprises: predicting the position of the movement of a target to obtain the predicted position of the target; extracting the prospect according to the obtained predicted position and determining a connected domain, making statistic to obtain the characteristic parameters of the connected domain; judging that the target characteristic update requirements are met by the result of the comparison between the characteristic parameters of the connected domain and the original characteristic parameters of the target, updating the original characteristic parameters of the target through the characteristic parameters of the connected domain matched during the comparison, and determining the position of the matched connected domain as the matched position for tracking the target. The invention is capable of well solving the problem that the characteristics of the target change in the process of tracking the target.