Lime-soil has been widely used in communication and construction engineering as a cheap building material. But in practice, there is a little knowledge about the properties and monitoring of lime-soil. In this paper, through laboratory experiments, the influence of curing age and lime-soil ratio on the properties, such as shear strength and compressibility, is studied. Results show that the engineering properties of lime-soil are ameliorated with curing age. It is especially notable within 30 days and the engineering properties are better when the lime-soil ratio is greater than 2.5:7.5. Finally, the micro-mechanism of strength development is analyzed. Test results are useful for monitoring and controlling the quality of lime-soil construction. A proposal is suggested that for the standard, one-month strength should be taken for designing and monitoring the lime-soil.