The normal distribution plays an important role in statistical analysis. However, a researcher may also wish to construct another symmetric distributions which fit the data better than the normal distribution. For this purpose, more flexible distributions have been introduced. In this thesis, we introduce some of such distributions. We first introduce the slash distribution as a family of mixed-normal scale distributions. The slash distribution can be used instead of normal distribution, in many situations. We also introduce Skew-slash. Then, a new modified-slash distribution is discussed. We also study a modified Skew-slash distribution. Some properties of the distributions discussed in this thesis are given. In particular, we present the stochastic representations, density functions and moments of the distributions.