PURPOSE: To provide a play instrument that can easily be assembled at a site in a short time by providing at least ≥3 circular arc frames radially from a center so as to essentially be formed in semi-spherical shape in an upper side part and fixing various kinds of play members on the lower part of the circular arc frames appropriately.

CONSTITUTION: This system play instrument 10 is provided with four circular arc frames 12 fixed mutually with a joint member 13 and set radially (crisscross shape) from the center so as to be formed substantially in nearly semi-spherical shape in the upper side part thereof. A pole 14 of prescribed length is provided between the free end 12a of each circular arc frame 12 and the ground GL, and the free ends 12a of adjacent circular arc frames 12 and the poles 13 respectively are mutually connected with a connection member 16. Also, the play member 18 such as a tire-swing, etc., is freely swingingly suspended on the lower part of each circular arc frame 12 from the center 0 via a robe-cord member 20.