A timing calibration system is applicable to a memory read system which includes a memory, a delay unit and a data read circuit. The memory outputs a data signal and a data latch signal. The delay unit delays the data latch signal by a delay value, to generate a read signal. The data read circuit reads the data signal according to the read signal. In the timing calibration system, a logic computation unit generates first and second charging signals according to the data signal and the read signal, and a capacitor-resistor charging unit performs charging operations according to the first and second charging signals, so as to generate first and second capacitor voltages, and a comparing unit can compare the first and second capacitor voltages, to generate a comparison result, thereby adjusting the delay value of the delay unit according to the comparison result.