A sectional LED lamp includes a base portion, a lamp portion, and a connecting unit. The base portion includes a base body having an LED driving unit provided therein. The lamp portion includes a lamp body detachably connected at an end to the base body, a lampshade fitted around the lamp body, and at least one LED chip arranged in the lampshade and electrically connected to the lamp body. The connecting unit is located between two adjacent ends of the base body and the lamp body for electrically connecting the LED driving unit to the LED chip and detachably connecting the base portion to the lamp portion. A space is maintained between the base portion and the lampshade, allowing heat generated by the LED chip to quickly dissipate via the space into surround environment.