Differential expression of genes in young fruit of cucumber (Cucumis sativus L.) before/after pollination was investigated via cDNA amplified fragment length polymorphism (cDNA-AFLP). There were 64 transcript-derived fragments (TDFs) displayed specially in young fruits after pollination of 6-72 h (Table 1), five of which were verified to be mainly expressed in young fruits by reverse Northern dot blotting (Fig.2). Sequence data showed one TDF was a new gene encoding expansin and was named as Cs-Expansin10 (CsExp10), which might be related to the expanding growth of cucumber fruit after pollination (Fig.3), another was significantly similar to the glutathione reductase gene, and the others had no similar sequence in GenBank database (Table 2).