⁴⁰K could be an important heat source during the evolution of the earth in that it may serve as a substantial heat source in the cores of the earth,sodium (Na) should be an important element in deep subducted slab,and subducted slab could transfer materials from the earth's crust to deep mantle of the earth. Moreover,garnet and clinopyroxene are common minerals in subducted slab. This paper presents a review of the progress in natural discovery and experimental study of K and Na behavior between garnet and clinopyroxene in the past five decades: ① the discovery of Na/K bearing garnet and its forming mechanism and significance; ② the discovery of K bearing clinopyroxene and its forming mechanism and significance; ③ experimental petrology study of K-bearing mafic-rock system. K,as a large ion lithophile element,could be incorporated into garnet and clinopyroxene under high pressure by substitution mechanisms of K^X+Si^Y=(Ca,Mg)^X+Al^Y and Mg^M1+Ca^M2=Al^M1+K^M2 respectively. It is significant for the K recycling from the crust to the deep earth. In subducting slab, Na could still be transferred into deeper mantle when clibopyroxene is not stable any more by the substitution of Na^X+Si^Y=(Ca,Mg)^X+Al^Y and the subsequent incorporation into garnet. K₂O content in clinopyroxene and Na₂O content in garnet present positive correlation with pressure according to previous high pressure-temperature experiments in K-bearing basalt/clinopyroxene systems under the mantle p-T conditions, while K and Na behavior in K-bearing basic rock system under the p-T condition of subducting slab remains rarely studied.