Micro nuclear reactors have drawn increasing attention in the past ten years in the nuclear industry. However, compared with traditional nuclear power plants, micro-reactors differ in a number of aspects, such as digital human-machine interfaces, multi-unit operation, remote and autonomous operation. These differences hinder the applicability of current human reliability analysis methods in the context of micro-reactors, which then poses challenges to the licensing of advanced nuclear technologies and systems. The objective of this research is to fill the gap between the capabilities of current HRA methods and the characteristics of micro-reactors. In this research, the candidate performance shaping factors affecting decision-making of operators in the context of micro-reactors were identified, and preliminary analyses of their effects on operator performance were conducted. To be specific, the characteristics of micro nuclear reactors which pertain to human performance were first identified based on an investigation of the designs and applications of micro nuclear reactors. These characteristics represent the contextual feature space for various micro-reactor designs and applications. Then, the effect of these characteristics on human performance was investigated by referring to relevant studies for nuclear systems as well as other similar systems. The results in this research will help extend the framework of current HRA methods to enable them to be applicable to advanced micro-reactors.