The concept of validity is difficult and often misunderstood. It is common to see the statement indicating that a “test is valid” in many research areas of validation studies, especially in physical activity research. Validity, however, cannot be definitely established with one or even two investigations. Rather, accumulation of various types of validity evidence is needed. According to the most recent edition of the Standards for Educational and Psychological Testing (AERA, APA, & NCME, 1999), validation is an ongoing process of accumulating various types of evidence to support the intended use and interpretation of test scores. The concept of validity had been changed from single, separate types to a unified concept, and the validity evidence based on a unified concept includes test content, response processes, internal structure, relations to other variables, and consequences of testing. These five possible sources of validity evidence are in need to be viewed as interdependent and complementary forms and not viewed as separate and substitutable validity types. The importance of physical activity has led many researchers to search for valid measures for physical activity. Usually, this is accomplished by correlating physical activity measures. To understand which validity evidence has been reported in validation of physical activity measures is important along with the new change in test validation. This presentation will briefly provide an updated review of new changes in test validation and review the validity evidences in the physical activity research under the new change in test validation.Keyword(s): . NA