Abstract: The visual model test based on synthetic transparent soil materials and PIV technology is one of the most important geotechnical engineering measurement technologies. However, there are still relatively few transparent materials which can be used for simulating the natural clay. A new transparent material which can simulate the natural clay is developed. It is manufactured by using Carbopol^® Ultrez 10, NaOH powder and distilled water, and nano materials are served as the tracer particles for spackle pattern. The manufacture processes are introduced. Based on the modulation transfer function (MTF) method, the transparency of this material is analyzed, and also compared with that of the previous transparent materials. Based on the laboratory vane tests, consolidation tests, falling head tests and thermal conductivity tests, the geotechnical properties of this synthetic transparent clay are measured. It is shown that the transparent clay presents a good optical transparency within 30~40 cm, which is 2~3 times that of the previous materials. This material is quite consistent with the low or middle-sensitive natural clay, and its strength increases with time obviously. It has similar shear strength and consolidation properties to the natural mud (especially marine mud). Its permeability ranges from 2×10^-7~7×10^-7 cm/s, and its thermal conductivity ranges from 0.62~0.71 W·M^-1·K^-1.