This study analyses in detail the iconography of seven Buddhas and bodhisattvas, the style and production technique of the monk sculptor Haengsa, and the context of production and art historical significance of the Clay Seated Sakyamuni Buddha Triad and Four Standing Bodhisattvas in Daeungjeon Hall of Gapsa Temple(Hereafter, the Clay Buddhas of Three Worlds in Gapsa Temple). The Clay Buddhas of Three Worlds in Gapsa Temple are the works of the monk sculptor Haengsa, made in 1617. They are clay-made sculptures of monumental size and are early examples of Buddhist sculpture from late Joseon. The contrast of the f lat upper body and the voluminous lower body is distinctive and the scheme of three Buddhas and four bodhisattvas is rare to find. The iconography of seven Buddhas and bodhisattvas have been understood as a variation of the Buddhas of Three Worlds and attending bodhisattvas, as the name “Maitreya” is written on the crown of a bodhisattva. Consequently, the three Buddhas are assumed to be the Buddhas of Three Worlds, namely, Sakyamuni, Bhaisajyaguru, Amitabha, and the four bodhisattvas, Manjusri, Samantabhadra, Maitreya, and Dipamkara. The concept of the Buddhas of Three Worlds encompassing all space and time, is an original iconography that displays the changes of three Buddhas and its context in the late Joseon period.