We present the results of a population study in Korea for four new tetrameric short tandem repeat (STR) loci employing multiplex PCR amplification, polyacrylamide gel electrophoresis of the PCR products and silver staining, which allow single base pair resolution and rapid typing. The loci tested were D18S1270, D14S608, D16S3253 and D21S1437 and all loci showed no significant deviations from Hardy-Weinberg equilibrium in more than 100 unrelated Koreans. This allelic frequency data can be used in forensic analyses and paternity tests to estimate the frequency of a multiplex PCR based DNA profile in the Korean population.