Root border cells are a population of rhizosphere cells surrounding but separated from the root apex. The root tip is the target of the Fe2+ toxicity, thus it was guessed that the border cells might function crucially in the response to the Fe2+ toxicity. To explore the excessive Fe2+ effects on the border cells in rice, experiments were carried out using the border cells in vitro (Shanyou No.10). The border cells were pre-planted in aeroponic culture and detached from the root tips. It is showed that the first border cell almost occurred synchronously with the primary root tip emergence. The numbers of the border cells reached its maximum (1311) when the root length was 25 mm. The viability of border cells reached the maximum of 74.05% when the root length was 20 mm. When the root length was 2 mm, the relative activity of PME (Pectin methyl esterase) reached the maximum. The PME may play an important role in production and development of the border cell in rice. The Fe2+ treatment decreases cell viability, when treated with 200 μmol•L-1 Fe2+ for 2 h, the cell viability decreased obviously, and most of the border cells in vitro had lost viability after treated with Fe2+ for 12 h, but the activity of the border cells added a little at 400 μmol•L-1 compared with that at 200 μmol•L-1. It could be due to a cellular self-protection response. With the addition of Fe2+ concentration, the PME activity increased and reached the maximum at 100 μmol•L-1 Fe2+, then decreased. These results suggested that Fe2+ toxicity on PME activity and border cell activity, and the PME activity may has an important role in Fe2+ toxicity.