Abstract: Plateau pika (Ochotona curzoniae) is one of the more abundant rodent species found in alpine meadow pastures in Tibet. Their foraging and burrowing activities accelerate the rate of degradation of alpine meadow pasture, and have a significant negative impact on the sustainable development of local pastoral farming. To quantify the impact of plateau pika, research was carried out in alpine meadow winter pastures at 4425 m altitude near Gengxing Township, Jiangda County, Nyingchi, Tibet (N 29° 87', E 93° 38'). The grassland type is referred to locally as ‘Bangjietang’ grassland. Data on pika burrow density, vegetation characteristics, and soil seed bank status were collected for two sites differing in degree of degradation (A, unfenced and more degraded; B fenced and less degraded) and within sites A and B for subplots impacted by pika activity, and subplots from which pika had been excluded by mesh cages. Pika burrow density was 547 ha^-1 (318 in use) at site A and 480 ha^-1(270 in use) at site B. Total area occupied by burrows and mounds was 161 m²·ha^-1 at site A and 120 m²·ha^-1 at site B. At site A, key data for plots unprotected and protected from pika, respectively, were: biomass 139 and 209 g DM·m^-2; species present 21 and 15; buried seed density 3929 and 4561 seeds·m^-2; species diversity index 2.28 and 1.63; and number of plant species represented in the seed bank 23 and 9. At site B, corresponding values were: 174 and 234 g DM·m^-2; species present 18 and 11; buried seed density 4559 and 5490 seeds·m^-2; species diversity index 1.95 and 1.19; and number of plant species represented in the seed bank 17 and 8. Plant species for which seed count in the seed bank was increased by pika activity were typically seed bearing and not rhizomatous. Hence it is concluded that plateau pika activity decreased grassland biomass and the number of buried seeds, but increased the species richness, particularly of seeded species. Additionally, the above effects of plateau pika activity were more pronounced at the more degraded site A than at the less degraded site B.