This paper aims to investigate writing activities in English textbooks, High School English I in terms of the students'' practical English writing skills and discuss the issues and remedy for the writing activities in English textbooks, High School English I based on these investigation. To achieve this purpose, this study carried out an analysis in the type and genre of the writing activities in English textbooks, High School English I from the perspective of achievement criteria, topics, sentence patterns, genres, and text construction types. Firstly, the result shows that overall writing activities in English textbooks, High School English I meet the achievement criteria for student''s writing skill in the curriculum except in some cases where textbooks do not reflect every items of the achievement standards evenly. Secondly, findings show that the topics in English textbooks, High School English I writing activities comply with the curriculum topics in general, however, most textbooks cover only a limited range of topic items failing to have them evenly distributed across the units. Thirdly, the type and scope of sentence patterns found in English textbooks, High School English I are not significantly different each other to the extent that ten to thirteen out of forty items of the sentence patterns in the curriculum are presented in its text. Fourthly, although English textbooks, High School English I in general include different genres of writing activities, there was a limit as to what the students could do when developing their writing skills for specific goals and situations because the students are rarely encouraged to involve in the activities for learning the characteristics of the genre targeted. Lastly, the majority of English textbooks, High School English I have a tendency to provide only limited types of text (‘explaining'', ''exchanging information'', ''describing, and ''proposing''). Based on the analysis results above, this study makes suggestions for the effective English writing instructions as follows: Firstly, teachers should create the teaching and learning content before delivering lessons to their students in a way a teaching goal is set toward specific achievement standard to help students get easier access to the achievement criteria of the curriculum. Secondly, teachers need to use diversified topics with segmented subjects, extend and transform the curriculum''s sentence patterns for the students to learn through the text or situation context, thus lead to a more significant and effective writing class. Lastly, to increase student understanding of genre-specific writing and improve writing skills, teachers should be able to provide writing activities that help students look into the contextual, structural, and linguistic features in the genre by giving them examples of the specific genre beforehand.