Abstract: This paper is the second part of the series results of "the preparation process of earth-quakes in group and the basic ways for their prediction".Based on the analysis of hydrochem-ical, water level and crustal deformation anomalies associated with three groups of strong earthquakes such as Xingtai-Haicheng-Tangshan earthquake group, Tanghai-Longling-Songpan and Dianbianfu-Lancang-Mandele earthquake groups, we have confirmed the fact that the anomalies of earthquake groups do exist, summed up their characteristics and pro-posed the principle and methods to identify them, It has been considered that, from the point of view of earthquake preparation in groups and based on the anomalies associated with earthquake groups, the grouping activity of strong earthquakes can be predicted, the activity range of earthquake groups can be determined and the developing tendency of earthquake groups can be identified.