A considerable number of studies have been conducted on second language (L2) writing, but not much interest has been gained in the study of L2 writing tasks for high school students. Adopting content analysis, the present study evaluates L2 writing tasks in four major and most widely used sets of Mainland Chinese English as a Foreign Language (EFL) textbooks, namely, PEP High School English, Advance with English (Oxford High School English), BNU High School English, and New Standard English for High School, to explore the characteristics of L2 writing tasks in Mainland China’s high school EFL textbooks and to examine whether these tasks meet the requirements of the New Curriculum Standard. Aiming to thoroughly examine L2 writing tasks, this study constructs a newly modified analytical framework to investigate the task type, genre, and topic of an individual L2 writing task, and to examine questions, including whether inputs are offered before writing, whether writing prompts are provided, what teaching method each task is adopted, and what approach the task requires students to conduct writing with. The study reveals that PEP High School English places greater importance to integrated tasks; Oxford High School English pays more attention to controlled writing and integrated tasks; BNU High School English contains more controlled writing than other task types; New Standard English for High School focuses more on free writing, controlled writing, and integrated tasks; and that BNU High School English pays little attention to integrated tasks and relies more on controlled writing tasks. Moreover, the graphological tasks in BNU High School English and New Standard English for High School do not conform to high school students’ actual writing proficiency. Results reveal that a variety of genres are contained in all four sets of materials, and the top two genres iv in each set of EFL textbooks, namely, description and letter/email/postcard, conform to the repetition of these genres in the New Curriculum Standard. However, practical genres, such as application letter, cover letter, curriculum vitae, and so on, are less featured in these materials. Furthermore, among the selected textbooks, BNU High School English contains the least number of genres. Results also reveal that these four sets of textbooks feature diverse topics and different emphases on writing topics: PEP High School English most frequently assigns topics of people and celebrities to students; Oxford High School English prefers to assign topics on future career/personal planning to students; BNU High School English is inclined to assign the topic of daily routine to students; and New Standard English for High School assigns the topic of arts more frequently than other topics. Topics covered in all these sets of materials correspond to the requirements in the New Curriculum Standard. BNU High School English also contains the least number of topics, similar to the case of genre. Additionally, no task requires teachers to use the process-based method. All tasks in the four sets of textbooks advise teachers to use either the product-based method or the genre-based method. In the era of modern technology, students’ approach to writing remains to be the paper-and-pencil mode, which is seemingly conventional, less modernized, and less convenient than computer-based writing. Furthermore, even though collaboration is highly recommended by the New Curriculum Standard, students are usually required to write individually rather than compose collaboratively, which is a mismatch between these EFL textbooks and the New Curriculum Standard. Comparatively speaking, BNU High School English is less satisfactory than PEP High School English, Oxford High School English, and New Standard English for High School in that the design of its writing tasks do not conform to high school students’ actual v writing proficiency and features of high-quality textbooks. Moreover, the limited inclusion of integrated tasks in BNU High School English set prevents students from developing their abilities to use integrated writing skills. On the basis of the discussion of the results, the researcher provides suggestions for materials development and in-class writing instruction at the end of the study.