Objectives The purposes of this study is to examine the effects of the factors in E-learning environment due to COVID19 on 2020 National Assessment of Education Achievement(NAEA) for English subject among high school students.
 Methods About 3 % of sampling classes were participated in NAEA. The achievement test results and the survey results of 10,526 2nd grade of high school students were used in the analysis except the missing values. The demographic characteristics(gender and regional scale) were served as the control variable and hierarchical regression analysis was used.
 Results The research results identifies the factors in E-learning environment affecting scholastic achievement of the English subject after controlling gender and regional scale. Model 1 explains approximately 3.6% and Model 2 shows about 11.9% of coefficient of determination respectably. Students who acknowledge the usefulness of E-learning have higher English scores. Also, students with higher English scores feel that E-learning environment is similar to that of school life. The variables such as ‘time used on private tutoring’, ‘time used on self-directed learning’, ‘anxiety on grade’, ‘interest in learning’ have positive correlation with academic achievement of the English subject. On the other hand, the variables such as ‘sense of belonging to the school’, ‘communication with the teachers regarding career plan’, ‘hangout time with friends’, ‘the amount of home work’, ‘the amount of study’, ‘communication with teachers regarding academic matters’, ‘life style on regular base’ have negative correlation with the academic achievement of the English subject.
 Conclusions The students with high level of English academic achievement tend to perceive that the amount of homework and that of learning are reduced in E-learning environment due to COVID19 compared to in-class learning environment. They feel more anxiety on grade, thus spend more time on tutoring and self-directed study in order to make up the lack of study. It is desirable that the results of current study help aware education gap caused by COVID19 and are able to served as a springboard to provide useful information to establish sound educational policy.