In the Guatemala jadeitite area, there are several rock types such as jadeitites, eclogites and albitites etc, among which omphacitite has not been reported in detail before. Jadeitite and omphacitite studied in this paper are from Guatemala jadeitite area, which is located in the Fault Zone between North America and Caribbean plates. Jadeitite mainly consists of jadeites with high content of Jd end-member, and has granular or coarser - grained mosaic texture. Most jadeites show rhythmic zoning; in cores and other light areas (BSE images), Jd contents are slightly lower (from 94.81% to 95.48%) relative to dark areas, where Jd contents are more than 97.92%. Omphacitite has metasomatic texture, mainly consists of omphacites and jadeites; omphacites have high CaO (9.01% ~ 10.80%) and MgO (6.09% ~ 7.94%), but low FeO (2.84% ~ 4.89%), jadeites have CaO (0.59% ~ 4.30%), MgO (0.26% ~ 3.05%) and FeO (0.76% ~ 2.87%). Presence of fluid inclusions in jadeites and textures of omphacite replaced by jadeite indicate the jadeitite was formed by crystallization from a jadeitic fluid, which subsequently leads to the replacement of adjacent pyroxenes, showing similarity to those from the Myanmar jadeitite. The zonal texture in jadeites reflects that the system of P-T-C varied rhythmically, and their straight and continuous boundaries indicate a HP/LT condition stable for jadeite crystallization. These petrographic features indicate that at least three stages of replacements existed, and the omphacitite wase possibly a production of replacement between jadeitic material and pyroxenite during formation of the jadeitite, and further indicate extensive infiltration of jadeitic fluid and diverse features of replacement within the subduction zone.