According to the mechanism of block of development in vitro culture on early embryo of mammal and in vivo surroundings of early embryo , the paper states that requirement and utilization of nutrients during each cell stage of early embryo of mammal in vitro culture in order to search for in vitro culture condition and method to improve the development rate of blastosphere 摘要从哺乳动物早期胚胎体外培养发育阻断机理和早期胚胎的体内环境入手，阐述了胚胎体外培养各细胞阶段胚胎对营养物质的需求，寻求合理的体外培养条件和方法，以便提高体外胚胎早期的囊胚发育率。
