Language testing is a kind of process to measure the competence or the achievement of the students in language, in this case English. Creating a set of test is not as simple as it seems; there must be many qualifications or requirements to consider to make a good test with good quality for the students. The objectives of this research are to know whether the English summative test for the tenth graders of SMA Negeri 1 Magelang in the school year 2015/2016 has good validity and represent the basic competence proportionally or not. The writer conducted the research by collecting the data. The writer took the question sheet of English first semester test as the subject of this study. The writer also took the English syllabus to analyze the test items. Then, the writer retyped the data and compared it with the syllabus. After that, the writer analyzed the test items one by one. Besides, the writer also counted the percentage of the conformity and unconformity of the test items to know the quality of the content validity of the test items. After analyzing the data, the writer finds that there are thirty-two items which conform to the syllabus and three items do not conform to the syllabus. Meaning that the English summative test has good content validity with the percentage 91.42%. But the representation of the basic competences do not proportional yet, because there is a basic competence which dominated the test items.