Abstract: The NutriGrade evidence quality grading system has established different quality of evidence grading methods for randomized controlled trials(RCTs) and cohort studies on which nutrition research evidence is based.The quality of evidence section of the NutriGrade for RCTs consists of seven assessment items：①risk of bias， study quality and study limitations(3 points)；②precision(1 point)；③heterogeneity(1 point)；④directness of evidence(1 point)；⑤publication bias(1 point)；⑥funding bias(1 point)；⑦study design(2 points). Each item is scored according to the scoring standard， and the scoring results of each item are finally summarized and transformed into four quality levels of evidence： high-quality evidence(8-10 points)， moderate-quality evidence(<8 points)， low-quality evidence(<6 points) and very low-quality evidence(<4 points).This paper systematically interprets the evaluation items and scoring criteria of this part of NutriGrade， and analyzes the application examples， in order to provide reference for domestic researchers to understand and apply this tool.

Key words: font-size:medium, ">Meta-analysis；Randomized controlled trial；Evidence classification；NutriGrade；Interpretation