A data transmission circuit which is improved to be capable of supporting a data transmission mode appropriate for an interface or an application depending on the selection of an option. The data transmission circuit includes a pre-driver configured to output a first differential driving signal, a second differential driving signal and pre-emphasis control signals by using a first differential data signal, a second differential data signal and option signals; a main driver configured to output a first differential transmission signal and a second differential transmission signal by using the first differential driving signal and the second differential driving signal; and a pre-emphasis driver configured to perform pre-emphasis on the first differential transmission signal and the second differential transmission signal to different amplification degrees in a first mode and a second mode by the pre-emphasis control signals.