It is of great significance to study the influence of spatial pattern change of cultivated land on ecosystem service, including the sustainable utilization and ecological protection in black soil region in Northeast China. Taking Lishu County of Jilin Province as the study area, we quantitatively evaluated soil conservation, habitat quality, carbon storage and grain production service, and analyzed the change of cultivated land and ecosystem service pattern in Lishu County from 1990 to 2020 by using Pearson correlation analysis on the correlation between cultivated land change and ecosystem service. The results show that: (1) The cultivated land area of Lishu County was reduced by 19.67 km², the characteristics of cultivated land change are significant; (2) the overall change rate of carbon storage, habitat quality, soil conservation and grain production service in the study area was 10.82%, −0.09%, 4.07% and 1.80%, respectively. They all had significant spatial differentiation features; (3) the change of habitat quality, grain production service showed a significant positive correlation with the change of cultivated land area. The change in soil conservation and carbon storage were negatively related to cultivated land area. In order to promote the rational development and utilization of cultivated land in the research area, it is suggested to scientifically carry out the comprehensive utilization of cultivated land reserve resources such as saline-alkali land, strengthen the management and protection of newly added cultivated land at the same time. The results can provide scientific reference for formulating comprehensive land use planning under ecological security conditions.

Jilin City is a typical river valley city in Northeast China. In this paper, the authors studied the spatial and temporal expansion characteristics of the built-up areas in Jilin City from 1990 to 2020 using the analysis of expansion speed and strength, fractal dimension, barycenter coordinate transfer index and sector analysis. The ultimate-goal is to analyze the driving and restrictive factors that affect the spatial expansion of river valley cities. The results indicate that (1) the expansion speed of urban land in Jilin City has been relatively slow in the past 30 years, while only slightly faster in 2010–2020; (2) in the spatial dimension, Jilin City mainly expanded to the south, then to the west, and extensive expansion has resulted in complex morphology with little stability and compactness; (3) the expansion is affected by multiple factors, of which the positive factor is industrial development, while the restrictive factors include natural factors, population loss, etc. This study provides a case for the formulation of land use policies and land space planning in river valley cities.