"Improvement in grades" 是表示成绩提高的常用说法。

来源：improvement 是英语中的动词，意为 "变得更好"，grades 是指学生在学校中所取得的分数或成绩。

例句：

He achieved an improvement in his grades after working hard on his studies.
他在努力学习后取得了成绩的提高。
She was pleased with the improvement in her grades from last semester.
她对上学期成绩的提高感到满意。
The teacher noted an improvement in the student's grades after implementing a new study strategy.
老师在实施新的学习策略后注意到学生成绩的提高。