Soil protists are the invisible majority of soil eukaryotes, which are essential but often forgotten parts of the soil ecosystem. They play key roles in microbial food webs by predating on other soil microbes. However, it is not clear how dormant soil protists sense, recognize and feed on diverse microbial prey. In this study, we used a soil amoeba, Dictyostelium discoideum, to study selective discrimination and predation of 14 different bacteria. We found that discrimination and sensing of prey in D. discoideum started as early as resting spores. Dictyostelium discoideum had higher hatching rates, formed bigger amoeba plaques and preferred high nutritional value bacteria. The feeding speed of amoeba on various bacteria was constant and was not linked with sensing of prey or bacterial nutritional value. We also found that higher bacterial density decreased predation efficiency, and one species, P. fluorescens, induced a strong density‐dependent inhibition of amoeba spore production. In conclusion, we find that dormant D. discoideum can selectively sense and predate on different soil bacteria, a process that is likely mediated through active amoeba preference as well as bacterial inhibition. This study provides new insights into the role of protists in shaping soil bacterial communities, and future study needs to assess this in natural soil environments. 摘要 土壤原生生物是土壤真核生物的主要组成成分，其在土壤生态系统中不可或缺但又经常被忽视。它们通过捕食土壤微生物来影响土壤微食物网。但是，休眠的土壤原生生物如何感知、识别和捕食它们的猎物尚不清楚。 本研究利用一种土壤阿米巴盘基网柄菌来研究其对十四种土壤细菌的选择性识别和捕食。发现盘基网柄菌在休眠期就已经可以识别其猎物：它们对高营养的细菌有着更高的孵化率，并形成更大的捕食阿米巴斑。但盘基网柄菌的捕食速率是恒定的，与细菌识别和细菌营养价值并没有相关性。我们还发现细菌密度会影响盘基网柄菌的捕食效率。其中一种细菌，萤光假单胞菌，表现出了非常明显的随密度增高而抑制盘基网柄菌生长的情况。 总而言之，本研究发现休眠期盘基网柄菌已经可以感知和捕食不同的细菌，其背后机制是由阿米巴主动识别和细菌抑制共同决定的。本研究为原生生物如何塑造和调控土壤微生物群落提供了新的视角，未来研究需要评估自然土壤环境中二者的互作模式。 A free Plain Language Summary can be found within the Supporting Information of this article. A free Plain Language Summary can be found within the Supporting Information of this article.