Currently as the emergence of high throughput technologies for omics data, such as yeast 2 hybrid protein interactions, researches of protein-protein interaction (PPI) had been explosively conducted on. One of the consensuses is that topographical analysis of the intercellular protein interactions lead to new avenues for drug target prediction. In this paper, a panorama view of drug targets is constructed. We found that the connectivity is often not a sufficient criterion to analyze the function of the drug target. On the other hand, the core of the PPI network poses a systematic way to consider the local and global significance of a protein, which indicates the inherent layer structure of the targets interactions. The analysis on core of the interactions shows that most of the drug targets are able to propagate the stimulus to some hub-like proteins and spread the transcription signal to others related proteins indirectly.