2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/201373Four-quark states are discussed within the constituent quark model. Incompleteness of existed studies of four-quark state with QCD sum rule is analyzed. The masses of diquark cluster were determined by QCD sum rules, and light four-quark states masses were obtained in terms of the diquark. The four-quark state possibility of the newly observed near-threshold p\bar p enhancement, X(1835), X(1812) and X(1576) by BES is discussed.4pages, no figure, PTPTEX, talk at the Yukawa International Seminar (YKIS2006), "New frontiers in QCD", Kyoto, JapanHigh Energy Physics - Phenomenologytext