This paper investigates the environmental pollution effects such as saline water, kerosene and sanitary leachate of cyclic wetting and drying on swell and shrink behaviour of compacted Na-bentonite clay. While the distilled water added Na-bentonite had the highest free swelling, saline water added Na-bentonite had the lowest free swelling among them. The experimental results showed that after each cycle, swelling and shrinking behaviour of compacted Na-bentonite clay were decreased. Honeycombe structure and random and more open flocculated structure dominated by large interdomain macrovoids and cavities were evident from salt water added Na-bentonite. Some domains and orientations were observed from distilled water added Na-bentonite micrographs. Aggregated and agglomerated structure were evident from kerosene added Na-bentonite micrographs.