Basing on the fragment (CO434610) cloned from cDNA amplified fragment length polymorphism (cDNA-AFLP), a 1191-bp cDNA sequence of CsEXP10 with a complete 3' end was obtained via rapid amplification of cDNA ends (RACE) and getting spliced with an EST (AF319471) of the same gene (Fig.2). Southern blotting analysis showed that CsEXP10 was a single copy gene in cucumber (Fig.5). The transcripts of CsEXP10 were detected by RT-PCR only in young fruit 3 d after pollination, but not in root, stem, and leaf (Fig.4A). At different developmental stages of fruit growth, Northern blotting demonstrated that CsEXP10 gene was expressed strongly in fruit 3 d and 10 d after pollination, especially the latter, but undetectable in ovaries of 2-3 cm in length and without pollination on the day flowering, and in fruits 26 d after pollination (Fig.4B). It is suggested that CsEXP10 might be highly correlated with the expansive growth of cucumber fruit.