[Objective] The spatiotemporal evolution of the relationship between carbon emissions and ecosystem service value（ESV） during land use changes in port cities was analyzed in order to support regional territorial spatial planning, ecological civilization construction, and green sustainable development. [Methods] Based on five phases of land use classification data of Qingdao City from 1990 to 2024, combined with energy consumption indicators, this study analyzed the spatiotemporal relationship between carbon emissions and ESV during land use change using the IPCC carbon emission coefficient method, the ESV equivalent factor method, and the bivariate spatial autocorrelation model. [Results] ① Substantial land use changes occurred in Qingdao City. Construction land increased by 1 478.13 km² during 1990—2024, which was mainly converted from cultivated land. Forestland first decreased and then increased, water areas showed dynamic changes, and grassland and unused land decreased.② Qingdao City was overall a net carbon source. Net carbon emissions exhibited dynamic changes, increasing by 18.25×10⁶ t. High-value zones were concentrated in the economically developed areas around Jiaozhou Bay, while low-value zones were distributed in the surrounding regions.③ ESV changed dynamically, exhibiting an overall downward trend, with a total decrease of 8.52×10⁸ yuan during 1990—2024. High ESV values were observed in areas such as the Jiaozhou Bay wetland and the Chizhi Reservoir in Laixi City, while lower values were found in the surrounding areas.④ The spatial correlation between land use carbon emissions and ESV in Qingdao City was complex and dynamic. The negative correlation showed an increasing trend, with significant local spatial clustering. High-low clustering zones were mainly distributed in the northern and eastern parts of Jiaozhou Bay. [Conclusion] It is necessary to strengthen the protection and ecological restoration of carbon sink land types such as forestland and grassland, control the speed of urban expansion, and appropriately adjust the industrial structure to promote carbon neutrality and ensure ecological security in Qingdao City.