The red imported fire ant, Solenopsis invicta, a serious invasive species, has caused striking ecological and economic impacts in China. Clarifying the occurrence of nest relocation in this pest is significant for understanding its ecological adaptability and formulating rational management strategies. However, despite a few reports on its nest relocation, little is known about the degree of nest relocation, seasonal features, and the possible differences among different habitats. In this study, we observed the nest-relocation dynamics of two social types (monogyne and polygyne) of S. invicta in a grassland in central Zhejiang Province, and we also investigated proportions of abandoned nests in 31 randomly sampled plots (mostly grasslands and green belts) in Zhejiang, Jiangxi and Guangdong provinces. Our results show that during the active seasons of monogynous S. invicta, their nests were abandoned in almost every period, with the proportion of such nests was evidently higher during February to July than following seasons. However, no significant quantitative relationship was found between abandoned nests and newly formed nests. A part of abandoned nests were reused every month, and the number of reused nests correlated positively with the total number of abandoned nests. The overall proportion of nests abandoned by polygynous ants was lower than that of by monogynous ants. Of the 31 plots investigated, 27 have a certain proportion of abandoned nests, with the proportions varying with habitats and locations. In the investigated green belts, most (80%) had an abandoned-nest proportion ranging from 10% to 35%, while nearly 70% of the grasslands had proportions of only less than 10%. For both green belts and grasslands, the abandoned nests reached more than 35% in some plots. This indicates that nest relocation, as a phenomenon frequently taking place in S. invicta life, varies substantially with seasons and may also be closely related with habitats and somehow social forms of this ant.