Objective　To explore the effect of human leukocyte antigen B* genotype and age on serum homocysteine (Hcy) levels in children with seizures or epilepsy. Methods　Fifteen children with seizures or epilepsy in whom HLA-B*15:02 genotype was detected during October 2015 to June 2016 were included. The plasma Hcy concentration in children with different genotypes was compared. The association of Hcy concentration and age was performed by linear-regression analysis. Results　The mean concentration of Hcy was 8.38±4.23 μmol/L in children not carrying HLA-B*15:02 gene, which was obviously higher than that in children carrying HLA-B*15:02 gene 13.03±0.97 μmol/L (P<0.05). The Hcy concentration increased with the age (r2 =0.29, P<0.05). Conclusions　Elder children with seizures or epilepsy carrying HLA-B*15:02 gene tend to have higher Hcy concentration and increased potential risk of disease. HLA-B*15:02 gene type and age  can predict the changes of Hcy concentration in children with convulsions.