A pet feeder includes an assembly base and a feeder body. The assembly base includes a base body having an annular external rim provided with a plurality of pluggable fins. The feeder body includes an annular surrounding wall and a feeding trough defined inside the surrounding wall. The surrounding wall of the feeder body is provided with several sets of slots arranged in a circumferential direction about a central axis thereof and annularly spaced from each other in the circumferential direction. Each of the several sets of slots extends a distinct depth and has a plurality of slots matching the pluggable fins of the assembly base. As such, a height of the feeding trough of the feeder body can be conveniently adjusted when one of the several sets of slots with a specific depth is coupled with the pluggable fins of the assembly base.
