Abstract: Disclosed is a temperature-compensated crystal oscillator based on analog circuit; a closed-loop compensation architecture determines the temperature compensation of a crystal oscillator. The power splitter divides the VCXO's current output signal with frequency f=f0+?f into two signals, one signal to output of the TCXO and the other signal is sent to an analog frequency-voltage conversion circuit. According to the frequency of the VCXO's current output signal, the analog frequency-voltage conversion circuit produces a voltage signal V(T), which corresponds to current ambient temperature. The difference between V(T) and a reference voltage signal Vref is produced and amplified to obtain a compensation voltage signal ?V through a voltage matching circuit. ?V is smoothed by a filter, then sent to the voltage control terminal of the VCXO to make the VCXO generate a stable signal with desired frequency f0, to compensate the frequency of the VCXO's output signal when the ambient temperature is changed.