Obsessive-compulsive disorder (OCD) is a common and severe mental illness, and its etiology still remains unknown. The glutamate transporter gene solute carrier family 1, member 1 was previously tested as a promising candidate for OCD by several research groups. However, subsequent studies were not consistent. OCD is a heterogeneous disease. Early-onset OCD is a demographically and clinically distinct subtype of OCD and may be a more homogeneous subtype. Gender-matched 244 early-onset OCD patients, 244 late-onset OCD patients, and 244 healthy controls were genotyped with four SNPs (rs10491734, rs2228622, rs301430, and rs301443) through TaqMan SNP genotyping assays. There were statistical differences in allele and genotype frequencies of rs10491734 in early-onset OCD patients compared to late-onset OCD or control subjects. The haplotype analysis showed that the four-locus haplotype (A-A-C-C and A-G-C-C) were associated with early onset obsessive-compulsive disorder after Bonferroni correction. The present study provided suggestive evidence that the rs10491734 was significantly associated with early-onset OCD in the Han Chinese population. However, these findings need further replication.