The moisture, temperature and electrical conductivity of soil are the important properties for agriculture. It is necessary to monitor such data in order to support the agricultural activities, especially improve the yield and reduce the irrigation water. However, the currently commercialized monitoring systems are too expensive for the smallholder who has less than two hectares of farmland. The objective of this study is to develop a cost effective system for monitoring the soil data, which consists of a monitoring device and a web-based application. The monitoring device measures the soil information every one hour and then transmits such data to the cloud for storing and visualizing. The system has been testing in the experiment field to evaluate the system’s stability.