To study the population data of Y chromosome STR (Y-STRs) of the Mongolian minority population residing in the Horqin district, we analyzed haplotypes of 26 Y-STRs (DYS19, DYS385a/b, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS481, DYS533, DYS549, DYS570, DYS576, DYS635, DYS643, DYS388, DYS449, DYS460, and YGATAH4) in 298 unrelated Chinese Mongolian individuals using the commercially available Goldeneye® DNA ID 26Y system. We also investigated blood stains, saliva spots, semen spots, hair follicles, fingernails, and sweat latent fingerprints from ten healthy males for testing the efficiency of direct amplification of this new Y-STRs system. The calculated average gene diversity values of the Mongolian population ranged from 0.3024 to 0.9510 for the DYS389I and DYS385a/b loci, respectively. The discriminatory capacity was 92.95% with 277 observed haplotypes using 23 Y-STR loci (DYS19, DYS385a/b, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS481, DYS533, DYS549, DYS570, DYS576, DYS635, DYS643, and YGATAH4). By adding three more Y-STRs (DYS388, DYS449, and DYS460) to the 26Y system, the discriminatory capacity was increased to 94.63% with a total of 282 observed haplotypes. Population relationships were calculated and compared with seven populations available from the Y chromosome haplotype reference database and data from ten Asian populations published previously. The Mongolian minority population residing in Horqin district is significantly different from other populations. Our results indicated that these 26 Y-STRs were highly genetically polymorphic in the Mongolian group and this contributes greatly to existing Chinese ethnic genetic information. As a result of direct amplification, we have obtained full profile from all blood stains, saliva spots, hair follicles, and fingernails; six semen spots; and one sweat latent fingerprint. It revealed that the 26 Y-STR system was a valuable tool for male sex analysis in forensic field and the kit was highly adaptive to direct amplification of various samples including blood stain, saliva spot, hair follicle, and fingernail.