The purpose of this research is: to describe the use of systematic, diction, effective sentence and spelling in the job aplication letter. The benefit of this research is to give knowledge and insight and give a picture of idea in writing job aplication letter. The method use in this research is describtive method with qualitative form which analyze the letter and explain the errors in the form of words. The data source of this research is the twelfth grade students of SMKN 2 Pontianak. Thre data used is job aplication letter which is done by the twelfth grade students of SMKN 2 Pontianak. The technique used in this research is measurement technique by means of knowing the ability of the students in writing job aplication letter. The result of this research revealed that there were still systematic errors in the letter address, content of the letter and the clossing greeting. Based oon the analysis, there was still a lot of errors in making the effective sentence.errors when using the spelling would include the use of capital letter, fullship and comma. 1