In this study of the medicinal plant, Pseudostellaria heterophylla, we obtained the national ecological factors, such as terrain factors, soil factors, and climatic factors, from Chinese medicine resources geospatial grid information database. An additional 46 samples and their distribution information were obtained through field investigation. We used cluster analysis to filter high polysaccharide contents in samples by using the ArcGIS and Maxent model for ecologically suitable planting and growth of P. heterophylla. Correlation analysis of polysaccharides and five climatic factors (wet season, warmest rain, warmest average temperature, driest month, and annual average temperature) were analyzed by SPSS. The following results are presented in this study. We screened sample plots down from 46 to 34 based on polysaccharide content. The models produced accurate forecasts, which were tested by the ROC curve (AUC > 0.9). Driest month precipitation (contribution rate, 68.4%), soil types (9.7%), warm-season average temperature (6.0%), and isothermality (4.0%) were the most important ecological factors influencing the distribution of polysaccharides in cultivated P. heterophylla. When comparing the three factors noted above (terrain, soil, and climatic), soil factors and climatic factors are more influential on the growth of cultivated P. heterophylla with respect to the distribution of polysaccharides. The environmental variables in the areas with the highest potential for cultivation were as follows: the driest month (between 20 and 60 mm of precipitation), the warmest average temperature (between 21.5 and 30.5°C), isothermality (between 18% and 35%), and soil types, such as Dystric Leptosols, Eutric Planosols, Chromic Luvisols, and Ferric Alisols. Correlation analysis revealed that polysaccharides and habitat suitability do not have a significant correlation with the wet season rainfall, warmest season precipitation, warm-season average temperature and precipitation, driest months, and annual mean temperature. It can be inferred that the production of polysaccharides is not dominated by the climatic factors. Regionalization analysis results showed that the most suitable areas for P. heterophylla planting are mainly distributed in the provinces of the middle and lower reaches of the Yangtze River area. Specifically, these areas include central Guizhou, which is bordered by Chongqing, Hunan, Hubei, southern Henan, western Anhui, central Jiangsu, northwestern Fujian, and northern and southeastern Zhejiang. These areas are within the Dao-di area, and are the main agricultural production areas. We used spatial analysis technology to select a suitable ecological area for P. heterophylla planting and provide information about a reasonable layout for its cultivation using climate, soil, and terrain characteristics. Finally, because the effects of polysaccharides and the positive supplementary effects of P. heterophylla roots are similar, we analyzed the content of polysaccharides as an indicator of high quality P. heterophylla using samples from five main producing areas in the country. We analyzed a wide range of material from a large sample size, and showed that reliable results can be obtained from samples within the Dao-di area. We also used new analysis methods to analysis our results. In this paper, the data covering ecological factors and degree of differentiation were highly accurate and offered more clarity than previous studies. Moreover, this study expands on research methods pertaining to the ecological suitability of regions for P. heterophylla cultivation and provides some new ideas and approaches on regional ecological zones and standardized cultivation of medicinal plants. Further, we have detailed useful information that will aid other medicinal plant research, especially endangered medicinal plant species.