High-quality software is a result desired by all users. Software qual-ity is a multidimensional concept and is influenced by many external and inter-nal factors. Testability is one of the most important factors affecting the quality of the software. The higher the level testability of a software, lower the testing effort and cost will be; therefore more reliable and higher quality products will ultimately emerge. Unfortunately we cannot directly measure the testability of software since it is not an intrinsic property of the software. Therefore, many proposals are set forth in the literature in order to measure the testability. Most measurement proposals are carried out based on the source code, but we note that it is more costly and complex to eliminate errors resulting from the analysis or implementation phases. The purpose of this article is to perform a literature mapping on the existing models and techniques that are targeted to measuring or predicting the testability.