Assessment in teaching in general and English teaching in particular is a major factor affecting teaching results. Therefore, the National Foreign Language Project 2020 (National Foreign Language Program 2020) has considered improving the foreign language testing and assessment competence for teachers as one of the pivotal tasks of the Project in the expansion duration from 2017- 2025. By means of a cross-sectional survey carried out in the summer of 2019, systematic random sampling with a sample size of 3103 Vietnamese English teachers at all 3 levels (primary school, middle school, secondary school) by regions (6 key areas in the country, including (1) Northern Mountain Region, (2) Northern Delta Region, (3) Central Region, (4) Central Highlands Region, (5) Southeast Region, and (6) Southwest Region), using quantitative statistical analysis tools, this article is to find out the perception of English teachers about knowledge of testing and assessment, and the actual implementation of assessment in daily teaching.