This study is on the historical research of the middle-gate in ancient temple especially Mireuksa in Baekje period. Through the comparative analysis of middle-gates in ancient temple and based on remains in Mireuksaji temple site, the plan of middle-gate in the site can be estimated. The results are as follows; First, middle-gate in middle area, east and west middle-gate in each area can be constituted in 3 kans in front by 3 kans in side. By the way it can be assumed that one of the later building sites was the middle-gate in the middle area by remains of stylobate and it can be constituted in 3 kans in front, and by relation with east middle-gate especially measure analysis the plan of the middle-gate in middle area can be constituted in $3{ imes}3$ kans in plan like as the middle-gates in east and west area. Second, the middle-gates in Mireuksaji temple site could be two stories. Therefore in plan of the middle-gate it could be considerated as important factor upper floor especially center bay(eo-kan, 御間). Third, the stylobate constitution of the middle-gate was separated from it of the side corridors in the middle area, and the stylobate constitution of the east and west middle-gates was connected with the side corridors. It can be assumed that it was caused the hierarchy and emphasis on the middle area.