The small-scale heterogeneity of seed bank was analysed in Huli marsh, a freshwater wetland. Sixty-four soil cores were collected from a 16m×4m grid area in December 2003. Two indices of pattern detection (variance/mean ratio and Lloyd’s index of mean crowding) and Morans I statistic of spatial autocorrelation were computed. In total, 17 species were detected from the seed bank. Two perennials, Eleocharis acutangula and E. tetraqueter, had greatest seed density in the seed bank. For all 7 species with frequency higher than 10%, the seed pattern was aggregated as indicated by two indices of pattern detection. Moran’s I statistic of spatial autocorrelation was significantly greater than E(I) at p=0.05 for three species. However, the other four species showed no significant difference from E(I) even though they were classed as having an aggregated distribution by the other indices. This suggests that the patch size of the four species is smaller than the distance between two sample unites (1 m).