We have formulated and calculated the differential cross section for the formation of the simplest double- nuclear cluster system, K ? K ? pp , in the reaction process p + p ? K + + K + + ? ? + ? ? ? K + + K + + K ? K ? pp , where ? ? is a quasi-bound K ? p state corresponding to the ?(1405) resonance. From a comprehensive study of the calculated effects of the binding and density of K ? K ? pp on the cross section, we find that the bound-state peak of K ? K ? pp dominates over the spectrum when and only when the system is dense. This is understood as meaning that the two ? ? doorway particles interact immediately within a short distance, assisted by a large momentum transfer (?1 . 8 GeV /c ) and a short collision length (?0 . 3 fm), which helps to enlarge the ? ? ?? ? sticking into a dense K ? K ? pp system. This mechanism is similar to that for a single cluster ( K ? pp ) formation, which has just been proven by a DISTO experiment. The K ? K ? repulsion causes an energy shift to somewhat lower binding and a reduction in the peak cross section, but does not change the basic character of this reaction. In second part of the present thesis, we have formulated the ?(1405) ? (??) 0 invariant-mass spectra produced in p + p ? p +K + + ?(1405) reactions, which can be applied to the analysis of experimental data. The spectrum shape is composed of the incident channel and the decay channel for any existing model for ?(1405). Available experimental data are analyzed to deduce the best fit mass and width of ?(1405). Keywords : Exotic structures, Kaonic nuclei, Double-kaonic nuclei, formation, Heavy ion reaction, pp collision