The invention discloses an integrated dimmable compact fluorescent lamp and a circuit used therein. The circuit comprises a dimming module for adjusting the brightness of the compact fluorescent lamp by controlling voltage frequency output to a driving module, wherein the dimming module comprises a control part and a frequency modulation part, and the control part is used for receiving first electric signals from an input module and feedback electric signals from the lamp tube of the compact fluorescent lamp, generating part of or all reference electric signals as the first electric signals, responding to external operation to adjust the reference electric signals, and outputting the reference electric signals and the feedback electric signals together to the frequency modulation part so as to control the voltage frequency output by the frequency modulation part; and the frequency modulation part is used for receiving the first electric signals from the input module, generating voltage frequency output by the driving module, and responding to the reference electric signals and the feedback electric signals together to adjust the voltage frequency.