This research aims to investigate whether there is a significant difference of the students’ writing achievement after the students were taught trhough pre-task planning and online planning or not. This research used quantitative method in collecting and analyzing the data. The participants were the students of eleventh grades of SMK Kosgoro Sribhawono East Lampung in Academic Year of 2016/2017. The main research instrument was the writing test. The t-tests were used in analyzing the data from pre-test and post test in the experimental and control group. The result showed that the use of pre-task planning could improve the students writing. It could be seen from the significant value of t-test was 0.000 which was lower than 0.05. This research also revealed that online planning could increase the students’ English writing. However, the last finding of this research revealed that there was no significant difference of the use of pre-task planning and online planning. Based on these findings, it can be concluded that there was small difference of the pre-task planning in content aspect and online planning in organization and language aspects. Both two types of planning have similar improvement on vocabularies and also no improvement on the mechanic of the writing. However, the pre-task planning is slightly better on improving students’ writing than online planning. Therefore, the teacher should optimize the use of pre-task planning before beginning the actual task so that the students could be able to prepare more and increase their confidence in composing writing.