Most of the sulphur dioxide in the atmosphere is anthropogenic by-product. It is one of the basic causes of acid rain worldwide. NAAQS set the level of sulphur dioxide in the atmosphere for the safety of human health and environment. Breathing of Sulphur dioxide becomes cause of many diseases concerned with respiratory system like Bronchitis, Asthma, etc. In the perspective of human health and environment protection continuous monitoring and analysis has become of great importance. Wavelet is a tool to analyze non-stationary signal and hence wavelet transforms provide excellent analysis of non-stationary time series of SO2 and extracts important information. Daubechies4 wavelet is orthogonal and compactly supportive and therefore, it is useful for multiresolution analysis of SO2 data. Wavelet transforms provide simple and accurate frame work for modelling the statistical behaviour of SO2 variation in the interest of public health and environment protection.