A method of foreground auto-calibrating data reception window for a DRAM system is disclosed. The method comprises receiving data strobe and data from a DRAM of the DARM system, capturing a data strobe clock according to the received data strobe, generating three time points with a period of the data strobe clock, sampling the data at the three time points, to obtain three sampled data, determining whether to adjust positions of the three time points according to a comparison among the three sampled data, and configuring the valid data reception window according to the positions of the three time points when determining not to adjust the positions of the three time points.