Abstract: Agriculture is the main occupation in India. Main resource of agriculture is water. The important climatic factor is water, which decides the growth of crops. If crops get required water supply then the desired growth of crops can be achieved. If crops get excess water supply then it is not possible to achieve desired crops growth. Therefore to reduce human effort and to supply required water to crop. This IoT based smart irrigation system using arduino is developed. This system will also reduce the excess water consumption. Water distribution will be even in different areas of the farm/field.KEYWORDS: Internet of Things (IoT), Smart Irrigation system, Arduino, Moisture, Temperature, Gas