Abstract: The investigation was carried out to evaluate the effects of five plant growth regulators (PGRs) on a normal-seeded cultivar of longan (Dimorcarpus longana Lour. cv. ’Wulongling’) for inducing abortive seeds. Results showed that all the five plant growth regulators induced some abortive seeds in certain extent. MH and 6-BA were preferable inducers. The best two treatments were 6-BA(100mg/L)+CPPU(30mg/L) and MH (800mg/L)+CPPU(30mg/L) were the best of all. It was seen that the weights of seeds were reduced by 38.5% and 38.0% respectively, compared with the control weights 9.77g and 8.42g. Total soluble solid contents are 18.57% and 18.23%. The degenerated seed percentages were 62.2% and 83.5%.