A lampshade-fixing seat structure including a fixing seat for fixing a lampshade. The fixing seat is substantially bowl-shaped and has a circumferential wall with a predetermined height. The lampshade is formed with an annular groove having outer rims. The lampshade-fixing seat structure further includes more than two stopper leaf springs. Each of the stopper leaf springs has a fixed section fixed on inner face of the circumferential wall of the fixing seat. The stopper leaf spring further has a first stopper section inward obliquely extending from the fixing section and a second stopper section obliquely extending from one end of the first stopper section in reverse direction. The first and second stopper sections of the stopper leaf spring resiliently abut against the outer rims of the annular groove of the lampshade to locate the lampshade in the fixing seat.