A kind of seat of controllable back tilting,It include a group,With one first limiting section,One second limiting section,One clamping piece,An and chair cushion； One back group,With a positioning rod part, it has an extension rod and a positioning region,And one the chair back can with respect to the positioning rod piece extension rod be displaced； When the positioning region is supported to the first limiting section of this group, the back system is first angle,When the positioning region is supported to the second limiting section of this group, the back system is second angle； When the back group what first angle,The clamping piece clip of the seat group lives the extension rod of the positioning rod piece.一種可控制椅背傾斜的座椅，包含有一座組，具有一第一限位部，一第二限位部，一卡掣件，以及一椅墊；一背組，具有一定位桿件其有一延長桿及一定位部，以及一椅背可相對該定位桿件之延長桿位移；當該定位部抵頂至該座組之第一限位部時該背組係為第一角度，當該定位部抵頂至該座組之第二限位部時該背組係為第二角度；當該背組於第一角度時，該座組之卡掣件卡掣住該定位桿件之延長桿。
