For long time, the use of standardized language test has dominated the language assessing practice. Assessment has focused on measuring how thoroughly students have mastered knowledge and skills. However, traditional standardized tests have been criticized for removing the human element and restricting communication between students and teachers; for eliminating the opportunity for students to draft and to revise their work; and for not allowing students to participate in choosing work that would better represent their abilities. The changes in education objectives lead to a change in assessment. Performance based assessment seems to be well suited in reflecting what a person can do. In contrast to measuring what they know, as found in formal measures, performance assessments measure how students can apply the knowledge they have acquired rather than what they perform in a test. This paper tries to raise the appropriateness of portfolios as a form of assessment that can allow students to see their own improvement over time, resulting in a sense of accomplishment as well as establish learning goals and to identify their strengths and their weaknesses.