Abstract: Since they were found in 1920’s, cosmic rays are investigated thoroughly for locating their sources. It is still one of 11 unsolved puzzles that drive people working hard in their own fields. Neutral components of the cosmic rays, photons and neutrinos are naturally selected as messengers between the source objects in the universe and us. It is also found that even if the ordinary charged cosmic ray particles can be used as such a messenger as long as their energies are sufficiently high, e.g. above 50 EeV. Large scale experiments in those fields form a frontier of a campaign for searching for the sources. Gamma ray astronomy seems to be the most successful and most likely to break through. In order to keep the strong momentum, a significant boost in sensitivity of survey observational power with wide field of view instrument is essential. The international observatory at Tibet, China has developed well with two major experiments, ARGOYBJ and ASγ, collaborating with Italy and Japan with the right techniques, namely air shower observation. We propose building a large complex array with five components at Yang Ba Jing, Tibet to boost the source survey sensitivity. Details about physics perspectives and tentative design are discussed in this paper.

Key words: cosmic ray origination, gamma ray astronomy, sensitivity, complex ground array