Abstract: Expression levels of 7 commonly used housekeeping genes including Actin（ACT），Cyclophilin（CYP），Elongation factor-1α（EF-1α），Glyceraldehyde-3-phosphate（GAPDH），Glyceraldehyde-3-phosphate 2（GAPDH2），α-tubulin（TUA）and β-tubulin（TUB）were detected by qRT-PCR in different Hippeastrum tissues and organs in this study. The stability of expression of these reference genes were evaluated by geNorm，NormFinder and BestKeeper respectively. The results of qRT-PR showed that EF-1α and GAPDH2 had high expressed level and stability；the second were TUB，TUA and GAPDH，respectively. According to the analysis of geNorm and NormFinder，both CYP and GAPDH2 were the relatively stable genes in different tissues and organs of Hippeastrum，followed by EF-1α. Although CYP had high expression stability，while its expression abundance was low. Thus，GAPDH2 and EF-1α could be as candidate reference genes for gene expression analysis. BestKeeper analysis indicated that EF-1α and GAPDH2 were in the high stability in different tissues and organs. According to the qRT-PCR and the three software results，it was found that EF-1α and GAPDH2 were suitable for the candidate reference genes. Then，the relative expression levels of Pistillata（PI）were detected，using EF-1α，GAPDH2 and EF-1α + GAPDH2 as reference genes. The results showed that the expression patterns were similar by using the three types of reference genes，and the expression patterns were referred to the mechanism of floral model that were higher in floral organs. Above all，EF-1α，GAPDH2 or EF-1α + GAPDH2 as reference genes were appropriate for gene expression analysis in Hippeastrum.

Key words: Hippeastrum vittatum, quantitative real-time PCR, reference gene, EF-1α, GAPDH2