A semiconductor memory apparatus includes a clock generator configured to generate an internal clock signal, an asynchronous data input buffer configured to buffer a data input signal through a data pad to output a buffered data signal, and a synchronous data input buffer configured to buffer the buffered data signal synchronously with the internal clock signal, wherein a length of a line, through which the internal clock signal is transmitted to the synchronous data input buffer, is configured to be substantially the same with a length of a line, through which the buffered data is transmitted to the synchronous data input buffer.