Communication by transferring data using computer networks have an important role nowadays. There are many activities which require sending or receiving data from one host to another. However, it can be a problem if the data is compromised during the transmission. In order to resolve the problem, steganography is used to secure the data. It is a data hiding method which can hide sensitive data in media so that unauthorized parties may not be suspicious or interested in attack. The previous reversible data hiding methods have been able to recover the image data and to improve the capacity of embedding. However, there are some problems that cannot be resolved such as overflow and underflow which result to decreasing the quality. In this paper, we propose a method which is able to overcome these problems that each pixel value on the cover image is expandable. The experimental results show that the PSNR and the capacity is higher than existing methods.