Adjusting chair

An adjusting chair, comprising:

• a seat frame;
• a backrest frame pivotally disposed at the seat frame and comprising a first rail, the first rail having a first guiding direction parallel to a length direction of the backrest frame, and the first rail comprising;
• a rail frame;
• and
• an inner pad disposed within the rail frame and forming a guiding space;
• a backrest sliding mechanism, comprising:
• a sliding element movably accommodated in the guiding space, the sliding element having a rod structure for coordinating with the guiding space;
• and
• a backrest assembly connected to the sliding element;
• a backrest linkage mechanism connected to the backrest sliding mechanism;
• and
• a driving mechanism connected to the backrest frame;
• wherein the driving mechanism drives the backrest frame to rotate relative to the seat frame, the backrest linkage mechanism drives the sliding element to move in the first rail, and the backrest assembly is moved relative to the backrest frame.