Latex is thought to be a protective substance associated with injury response in rubber trees. Tapping can significantly promote rubber production, which should be closely related to the expression of genes involved in rubber biosynthesis in the laticifer cells of rubber trees. However, the exact relationship between the expression of the rubber biosynthesis genes and the dry rubber yield is yet to be elucidated. In the present study, qPCR was used to analyze the expression of six rubber biosynthesis genes, HbHRT2, HbSRPP, HbREF, HbHMGR1, HbHRT1 and HbGAPDH, in the laticifer cells of five Wichham germplasms and five 1981°IRRDB germplasms following tapping them with S/2 d/3 tapping system. The results showed that the expression of these genes was significantly higher in most Wichham germplasms than in 1981°IRRDB germplasms, as shown by fold increases of 1.05-14.62, 0.97-4.26, 1.46-12.56, 0.83-2.99, 0.43-7.54, 1.92-11.31, respectively, for HbHRT2, HbSRPP, HbREF, HbHMGR1, HbHRT1 and HbGAPDH. Correspondingly, the average fold change was 7.54, 2.55, 5.69, 1.71, 2.71, 4.91. Correlation analysis showed that the expression level of these genes was positively related to dry rubber yield. Two of the genes, HbREF and HbGAPDH, could be exploited as the molecular markers in high rubber yield breeding programs for both genes showed a highest correlation between their expression level and the corresponding rubber yield.