No curriculum model would be complete without an assessment component. Language assessment is known from researches to be the most powerful influence on student learning but it has by far merely focused on summative one. Summative assessment emphasizes the memory of discrete language points and linguistic accuracy and neglects students active involvement and self-assessment in language learning. Emerged under humanism, constructivism and the theory of multi-intelligence, formative assessment lays emphasis on the diversity of testing forms, contents and methods. It aims at improving instruction, promoting development, and providing decision-making information. The New College English Curriculum Requirements proposes the establishment of combining formative assessment and summative assessment to assess studentsability to use English in an all-round way. The significance and necessity of formative assessment have been well acknowledged in the educational field. However,researches on the theory and practice of formative assessment are mainly carried out in the field of elementary education. Rarely have researches and experiments been carried out at college level. This thesis is a study on innovation of assessment in college English teaching.The experiment was conducted to find out whether formative assessment could facilitate the improvement of college students English learning. 90 art major students of two classes of Zhejiang Sci-Tech University were involved in the study. Mid-term exam scores showed that they were nearly at the same English level. The two classes were divided into the control and the experimental class. Formative assessment was integrated into the teaching of the experimental class. Summative assessment was adopted in the control class. Portfolios, observations, questionnaires, interviews and different studying tables were served as experiment tools. These tools were chosen because they could embody the applying of humanism, constructivism and the theory of multi-intelligence into teaching practice. After 8 weeks experiment, by analyzing data collected in the experiment, findings are drawn as follows: formative assessment can strengthen students motivation; improve students performance in tests and transform students into autonomous learners. Although the experiment expands the present practice and provides reference for further research, its limitations are as follows: short experiment time; limited students majors; small sample etc.. This thesis consists of four chapters. Chapter One serves as an introduction which provides the overview of the development in foreign language teaching assessment at home and abroad, setbacks of the current traditional teacher-centered approaches to English teaching, innovation in assessment in College English Curriculum Requirements. Chapter Two elaborates on three theories supportive of formative assessment:humanism, constructivism, theory of multi-intelligence in section one. Section two and section three are devoted to the characteristics and functions of formative assessment. Section four focuses on the comparison between formative and summative assessment. Section five illustrates the widely used formative assessment tools and techniques. Related studies are presented in section six. Chapter Three is the main body of the thesis. It presents an empirical study of implementing formative assessment into college English teaching. The objectives of the research, hypotheses, research design, including the backgrounds of students,instruments, method, data collection, data analysis, results and discussions are expounded. With all the work done, the thesis comes to a conclusion in Chapter Four. The study has proved that formative assessment is effective in strengthening studentsmotivation; cultivating leamer autonomy and helping students achieve better performance. The limitations and suggestions for future study are also pointed out.