PROBLEM TO BE SOLVED: To provide a circle for a pet which forms a new extension space on an outer side of a circle body by using an existing member, thereby avoids contact among pets when the pets are accommodated plurally and efficiently trains a pet when the single pet is accommodated.SOLUTION: Adjacent ends 21, 21 in a width direction of plural fence members 2 including a frame body 20 composed of right/left vertical rods 22 and upper/lower horizontal rods 23 are connected in a linear part with a linear part fixture 3 and connected in a corner part 12 with a corner part fixture 4 to form a circle body. One of the fence members 2 is replaced with a gate fence member 6. On an outer side of the gate fence member 6, a circle extension body 5A is arranged continuously. The end 21 in the width direction of each fence member 5 positioned in both ends in a right/left direction of the circle extension body 5A is connected with the end 21 in the width direction of the fence member 2 of the circle body with a vertical rod fastener 34 in a state in which both front/rear sides 211, 212 of the vertical rods 22, 22 abut each other.SELECTED DRAWING: Figure 6COPYRIGHT: (C)2016,JPO&INPIT【課題】既存の部材を用いてサークル本体の外側に新たな拡張空間を形成することで、複数のペットを収容した際のペット同士の接触を回避し、かつ単数のペットを収容した際のペットの躾を効果的に行うことができるペット用サークルを提供する。【解決手段】左右の縦杆22と上下の横杆23とからなる枠体20を備えた複数枚の柵部材2の互いに隣接し合う幅方向端21,21同士を直線部で直線部用固定具3により連結すると共に角部12で角部用固定具4により連結してサークル本体を形成し、その柵部材2の1つを出入口用柵部材6に置換する。この出入口用柵部材6の外側にサークル拡張体5Aを連設する。サークル拡張体5Aの左右方向両端に位置する各柵部材5の幅方向端21をサークル本体の柵部材2の幅方向端21に対し、互いの縦杆22,22の表裏両側辺211,212同士を突き合わせた状態で縦杆用締結具34により連結する。【選択図】図6