Based on the sequences of CsACS1G, CsACS1 and BCAT, the specific PCR primers were designed to identify CsACS1G gene using DNA markers in Cucumber (Cucumis sativus L.), and genome DNA was rapidly extracted from cucumber WI1983G, 95, 98-17, S2-98 and offspring 95×WI1983G with the method of NaOH. Field surveys were conducted in the flowering period so as to confirm stability of the primers. The results showed that DNA molecular marker can amplify a specific fragment of CsACS1G gene when the resultant DNA was used as PCR template. So, identification of CsACS1G gene DNA molecular markers and the method of DNA rapid extraction in cucumber would provide the conditions to accelerating breeding of gynoecium’s cucumber.