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Surface (0~7.5cm) soil water content (SWC) was measured at 82 locations in a typical alpine meadow ecosystem on the northern Tibetan Plateau by using time domain reflectometry for 14 times during the 2015 growing season to evaluate spatial variability and temporal stability of surface SWC. Results showed that the mean SWC of the two transects during the 2015 growing season was 26.0%. SWC had a weak variability in space and a moderate variability in time. The variability of SWC was increased with the increase of SWC. The spatial pattern of SWC at the 82 measuring locations had a weak similarity during July and early August and a strong similarity from middle August to early September. The mean relative difference (MRD) of SWC was from -11.5% to 8.5% and the mean standard deviation of relative difference (SDRD) was 8.6%. MRD was correlated with SDRD in a concave curve relationship. Index of temporal stability, mean absolute bias error, root mean square error and minimum-SDRD constant methods could all identify the best representative location and the accuracy of mean SWC estimation of the representative location was high. Comparatively, the minimum-SDRD constant method had a higher accuracy. This study can provide data supplement and method innovation for SWC study in alpine meadow ecosystems.