This paper constitutes a discussion of the desirability of standardization of corrosion tests and of the difficulties and pitfalls involved. A brief historical review of attempts to standardize corrosion testing is given, and the various types of tests are classified into three broad groups: (1) laboratory; (2) field; and (3) service. A short review of the theory of corrosion and a discussion of the factors influencing the corrosion rate is given. Various methods of estimating the extent or rate of corrosion, together with methods of presentation and interpretation of data, are discussed critically. Corrosion tests are examined from the standpoint of the functions they are to fulfill, such as: the selection of suitable materials for a definite environment, the development of new alloys, the control of the product, etc. The advantage of special-property tests over accelerated life tests is stressed. Special-property tests are defined as those which attempt to determine a specific characteristic of the metal or alloy. Among such tests are those to determine the susceptibility of the metal to pitting, season-cracking, dezincification, etc. Tests such as the salt-spray or immersion can be employed either as special property tests or as accelerated life tests depending on the attitude of the user and his interpretation of the results obtained. As the ultimate purpose of this symposium is the possibility of standardization of corrosion tests, an attempt has been made to divide the various tests into two groups: those ready for standardization, and those requiring more investigation before they can be standardized.