This study was conducted to detennine the suitable time for tree-base mulching by plastic sheet before harvesting time to decrease the physiological disorder of Sua hat lep durian (Durio zibethinus Murr.). This experiment was carried out on 7 years old tree gown in Cho Lach district, Ben Tre province in 2011. Four treatments i.e. mound was arranged in completely randomized design, 3 replication, each replication equal to one tree (mulching at 15, 20, 25 days before harvesting time and control treatment un-mulching). The results showed that mound mulching at 25 days before harvesting time caused decrease soil humidity to 40 em (21.71 percent), high total solid solution (14.76°Brix), no overmoist flesh and tip bum. Rate of physiological disorders was positive relative with soil humidity at 0-20 cm-depth and Mg content in leaf in havesting time.