If we insert a bypass capacitor in a common emitter amplifier circuit, will it increase the upper corner frequency of the amplifier?

 

It will increase the amplifier gain as the frequency increases.

Show your circuit schematics.

 

It depends on the frequency range of the amplifier and the values of the emitter resistor and bypass capacitor. Show your circuit and let us know the details, then we can give you a definite answer.
Regards,
Keith