A rotary umbrella seat for an umbrella, comprising: a rotary base; a sleeve welding piece fitted through the rotary base; and a pedal component attached to the rotary base; the sleeve welding piece comprises a sleeve connected to a base plate; the sleeve is a vertically post disposed in the middle of the base plate and is welded with the base plate; the rotary base is sleeved outside the sleeve and located above the base plate; such that a lower end of a column of the umbrella is slidable over the sleeve and adapted to rest on the rotary base; said rotary umbrella seat further comprising a pedal component which comprises a pedal connected to a pedal shaft; the pedal is resetably and rotatably attached to the top of the rotary base; the base plate has a plurality of positioning holes, the pedal shaft passes through the rotary base and is inserted into one of the positioning holes on the base plate, such that the pedal shaft is disengaged from the base plate when the pedal is pressed down during the rotation of the pedal, and the pedal shaft is engaged to the rotary base when the pedal is released; wherein the rotary base is a circular base with a hole formed in the central of the rotary base; the rotary base has a cylindrical boss formed at the hole of the rotary base; the lower end of the sleeve passes through an inner hole of the boss and is fixed to the base plate; the rotary umbrella seat further comprising a seat tube plug which is disposed at an opening position on the top of the sleeve, and a rotary block is sleeved on the upper end of the sleeve; such that the rotary block is adapted to rotate with the column, and is rotatably sleeved on the upper end of the sleeve and is covered by the seat tube plug. a rotary base; a sleeve welding piece fitted through the rotary base; and a pedal component attached to the rotary base; the sleeve welding piece comprises a sleeve connected to a base plate; the sleeve is a vertically post disposed in the middle of the base plate and is welded with the base plate; the rotary base is sleeved outside the sleeve and located above the base plate; such that a lower end of a column of the umbrella is slidable over the sleeve and adapted to rest on the rotary base; said rotary umbrella seat further comprising a pedal component which comprises a pedal connected to a pedal shaft; the pedal is resetably and rotatably attached to the top of the rotary base; the base plate has a plurality of positioning holes, the pedal shaft passes through the rotary base and is inserted into one of the positioning holes on the base plate, such that the pedal shaft is disengaged from the base plate when the pedal is pressed down during the rotation of the pedal, and the pedal shaft is engaged to the rotary base when the pedal is released; wherein the rotary base is a circular base with a hole formed in the central of the rotary base; the rotary base has a cylindrical boss formed at the hole of the rotary base; the lower end of the sleeve passes through an inner hole of the boss and is fixed to the base plate; the rotary umbrella seat further comprising a seat tube plug which is disposed at an opening position on the top of the sleeve, and a rotary block is sleeved on the upper end of the sleeve; such that the rotary block is adapted to rotate with the column, and is rotatably sleeved on the upper end of the sleeve and is covered by the seat tube plug.