Species abundance and distribution are often correlated, such that the positive abundance-distribution pattern means the widespread species tend to be abundant, and narrowly distributed species rare. Several hypotheses have been proposed to explain the positive relationship between abundance and distribution, but the mechanisms behind this pattern still remain poorly understood. Among these hypotheses, the niche breadth and the niche position (or habitat availability) hypothesis are the most investigated, since the niche-based model predicts that both distribution and abundance mirror the degree to which local environmental conditions meet the requirements of species. We used outlying mean index to measure the niche position and the niche breadth of each species in the 436 quadrats collected in the three estuaries of the Yellow River Delta. The distribution of each species was represented as the number of sites occupied. We tested the relationship between the distribution and abundance of plant species with a specific aim to examine if this relationship follows the mechanistic basis of the niche-based (niche breadth and niche position) hypothesis. We estimated the relationship using ordinary least-squares regressions. There was a significant positive relationship (R²_a=0.75) between the distribution and abundance of the plant species. We found a significant positive relationship between the niche breadth and abundance, and the regional distribution. The niche breadth explained 19% of the variation in abundance but 42% of the variation in distribution. There was a significant negative relationship between the distribution and the niche position, but the relationship between the abundance and the niche position was not significant. The niche position explained 46% of the variation in distribution. These results suggest that some widely distributed species tend to be, on average, locally abundant, and have wider niche breadth and lower marginality of niche position with regard to the environmental factors than the species that have more restricted distributions. When the relationship was significant, both the niche position and the niche breadth explained less than half of the variation in abundance and distribution, this suggests that not only niche-based processes, but also other mechanisms are likely to act in concert in determining the relationship between distribution and abundance of the plant species. Although there was some unexplained variability around the relationship, the niche breadth was more consistently related to the positive abundance-distribution relationship than the niche position. The positive pattern generally exhibited by the abundance-distribution relationships, has consequences for several areas of applied ecology, including conservation, harvesting, biological invasions and biodiversity inventory.