Background and Purpose: As a growing number of instructional units have been developed to promote young children's scientific and engineering practices (SEPs), understanding how to evaluate and assess children's SEPs is imperative. However, paper-and-pencil assessments would not be suitable for young children because of their limited reading and writing skills. To explore the assessments for SEPs available for young children aged 3-8 years, this study reviewed assessments of young children's SEPs reported in empirical studies, and analysed the characteristics of these assessments to delineate how young children's SEPs have been measured. Methods: We followed the procedures of a systematic review proposed by Zawacki-Richter et al. (2020). The EBSCOhost database was used to gather empirical studies in education and psychology. A total of 46 articles published from 2003 to 2020 met the inclusion criteria and were reviewed. Findings: The findings indicated that of the eight SEPs suggested by the National Research Council (2012), "Analysing and interpreting data" was assessed the most, followed by "Using mathematics and computational thinking, Constructing explanations and designing solutions," and "Planning and carrying out investigations." A majority of assessments were designed for children of 4, 5, and 6 years old and used paper-based visualizations and real objects to present the tasks and items. Additionally, due to the verbal or performance nature of the SEPs, the assessments collected different types of data as evidence to evaluate children's SEPs. Performance-based assessments were the most common, followed by multiple-choice, ranking, and oral responses. Conclusion: The findings of the reviewed assessments revealed a variety of performance expectations of SEPs and suggested that some SEPs are measurable and developmentally appropriate for young children. Also, the availability of assessments is uneven in different types of SEPs, and more assessments for information communication and modelling practices are needed.