Flush toilet apparatus

A flush toilet apparatus capable of executing a large flush mode and a small flush mode, the flush toilet apparatus comprising:

• a flush toilet main body that includes a bowl, a water discharge trap pipe communicating with a lower portion of the bowl, an upper water discharge port provided above a pooled water surface of the bowl, and a lower water discharge port provided below the pooled water surface;
• and
• a flush control device configured to control water discharge of flush water from the upper water discharge port and the lower water discharge port to execute the large flush mode and the small flush mode in which a flush water amount is smaller than the flush water amount in the large flush mode,
• wherein the flush control device causes the flush water to be discharged from the lower water discharge port with substantially the same amount in each of the large flush mode and the small flush mode to induce a siphon phenomenon in the water discharge trap pipe, while controlling the water discharge from the upper water discharge port so that a water level of pooled water in the bowl during the water discharge from the lower water discharge port is different between the large flush mode and the small flush mode.