Abstract: The widespread adoption and deepening use of internet technology have had growing impacts across many areas of society, particularly in the domain of marriage and family. Using panel data from 31 provinces, autonomous regions and municipalities in China from 2010 to 2020, this study employs a panel threshold model to examine how internet development affects the marriage rate. The results show that, as economic development progresses, internet development exhibits a significant single-threshold effect on the marriage rate. First, internet development has a significant negative effect on the marriage rate, with stronger effects observed in economically less developed regions. Second, heterogeneity analysis shows that although no threshold effect is identified in the eastern, central, or western regions, internet development still negatively affects the marriage rate in all regions, with a greater impact in economically less developed areas within the eastern and central regions. Overall, the findings suggest that the influence of internet development on the marriage rate varies with the level of economic development, and that economic development tends to mitigate the internet's negative impact on marriage rates.