In this study, a glycerol 3 phosphate acyltransferase gene, named HaGPAT1, was isolated from oil sunflower seeds. The length of HaGPAT1 is 1 656 bp, encoding 551 amino acids with calculated molecular mass of 62.132 kD and isoelectric point (PI) 8.84. The expression profile of HaGPAT1 was detected by quantitative realtime PCR (qRTPCR) in different tissues through different developmental stages of seeds and under abiotic stress treatments. Multiple sequences alignment showed that HaGPAT1 was closely related to GPAT1 protein of higher plants. The expression of HaGPAT1 reached its highest level in buds and upregulated under drought and salt stresses. The results suggested that HaGAT1 might play an important role in floral organ development and may be involved in abiotic stress regulation of sunflower.