Abstract The use of appropriate leaching tests and leaching models can help to predict the hazardous components release from cementbased solidified waste during either utilization or disposal. Numerous parameters influence the leaching rates such as grain size/specimen size,ccc liquid-to-solid ratio, pH value of the leachate, leaching time etc. This study evaluates the effect of initial liquid-to-solid ratio of cement paste on the release of copper from cement-based solidified waste. Dynamic leaching tests were performed to determine the rate of constituent release as a function of initial liquid-to-solid ratio of cement paste. The results have showed an increasing of copper leachability with liquid-to-cement ratio. The mechanism of copper release was investigated under diffusion control. Using a simple leaching model, the leachability indexes of copper (LI = pDobs - the rate of leaching) for all situations were calculated. All the leachability indexes of the cement specimens far exceeded the standard value (LI > 12.5) showing that the copper in the samples has a low mobility.