The objective of this study is to estimate the impact of plot size on productivity growth. Accordingly, we measured the size of nearly 4,000 plots using satellite images and merged them with city-level agricultural statistics for southeastern China. The main findings are as follows. First, the results show that plot size is inversely correlated with land productivity growth. The results showed that a 10% decrease in plot size would accelerate the annual growth rate by 0.10 percentage points. Second, to clarify the mechanism behind the inverse relationship, the study shows that small-plot farmers are more willing to shift their crop types to high-value crops than large-plot farmers.