通过实际调查以及查阅中国数字植物标本馆、全球生物多样性信息网络和相关文献，共收集半日花（Helianthemum songaricum Schrenk）在中国的58个有效分布记录。基于MaxEnt、BIOCLIM和DOMAIN模型以及19个环境变量，采用受试者工作特征曲线下面积（AUC）检验模型预测精度，预测末次间冰期、末次冰盛期、当代（1950年至2000年）和未来（2050年）4个时期半日花在中国的潜在适生区，并采用刀切法（jackknife）和主成分分析法评估影响半日花潜在适生区的主导环境变量。结果显示：MaxEnt、BIOCLIM和DOMAIN模型的AUC值分别为0.984、0.837和0.962，预测精度分别为很好、一般和很好。MaxEnt、BIOCLIM和DOMAIN模型的预测结果显示：当代半日花潜在适生区面积分别占中国总面积的3.19%、7.63%和5.62%，主要呈破碎化和狭长间断分布，分布于内蒙古、新疆、宁夏、甘肃、陕西和山西；未来半日花潜在适生区面积分别占中国总面积的2.95%、9.55%和7.09%，其中，高适生区面积分别占中国总面积的0.42%、0.11%和0.49%，潜在适生区向内蒙古鄂托克旗西部和乌海市以及内蒙古阿拉善左旗东部与宁夏北部交界处骤缩。影响半日花潜在适生区的主导环境变量为温度（年均温、最冷月最低温、最热季度均温和最冷季度均温）和降水（最热季度降水量和最湿季度降水量），且温度的影响较大。

There were 58 valid distribution records of Helianthemum songaricum Schrenk in China collected by field investigation and consulting Chinese Virtual Herbarium， Global Biodiversity Information Facility and related literatures. Based on MaxEnt， BIOCLIM and DOMAIN models and 19 environmental variables， prediction accuracy of models was evaluated by area under the receiver operating characteristic curve （AUC）， potential suitable areas of H. songaricum in China under four periods of Last Interglacial， Last Glacial Maximum， current （from 1950 to 2000）， and future （in 2050） were predicted， and dominant environmental variables affecting potential suitable areas of H. songaricum were evaluated by jackknife test and principle component analysis. The results show that AUC values of MaxEnt， BIOCLIM， and DOMAIN models are 0.984， 0.837， and 0.962， and their prediction accuracy is good， normal， and good， respectively. The prediction results of MaxEnt， BIOCLIM， and DOMAIN models show that areas of potential suitable areas of H. songaricum in current account for 3.19%， 7.63%， and 5.62% of total area of China， respectively， which mainly appear fragmented and narrow disjunction， and distribute in Inner Mongolia， Xinjiang， Ningxia， Gansu， Shaanxi， and Shanxi. In future， areas of potential suitable areas of H. songaricum account for 2.95%， 9.55%， and 7.09% of total area of China， respectively， in which， areas of high suitable areas account for 0.42%， 0.11%， and 0.49% of total area of China， respectively， potential suitable areas decrease sharply to western Otog Banner and Wuhai City in Inner Mongolia， and the junction of eastern Alagxa Left Banner in Inner Mongolia and northern Ningxia. Main environmental variables affecting potential suitable areas of H. songaricum are temperature （annual mean temperature， the minimum temperature of the coldest month， mean temperature of the warmest quarter， and mean temperature of the coldest quarter） and precipitation （precipitation of the warmest quarter and precipitation of the wettest quarter）， and the effect of temperature is bigger.