Touch input system and method for detecting touch using the same

A touch input system and a touch detection method using the same are disclosed. With the disclosed touch input system, the size and manufacturing costs of the stylus are reduced while finger touch and touch of stylus without a battery are distinguished and detected. The touch input system includes a sensor panel including a plurality of first channels and a plurality of second channels, crossing each other, a stylus including one or a plurality of primary coils connected in series to each other, a resonance capacitor connected in parallel to the primary coil, and a conductive tip connected to the primary coil, a ground connected to the stylus, an antenna loop formed outside an edge of the sensor panel, and a touch controller connected to the first channel, the second channel, and the antenna loop.