This study explored the potential of using probabilistic neural networks (PNN) to predict shrinkage of thermal insulation mortar.Probabilistic results were obtained from the PNN model with the aid of Parzen non-parametric estimator of the probability density functions (PDF).Five variables,water-cementitious materials ratio,content of cement,fly ash,aggregate and plasticizer,were employed for input variables,while a category of 56-d shrinkage of mortar was used for the output variable.A total of 192 groups of experimental data from 64 mixtures designed using JMP7.0 software were collected,of which 120 groups of data were used for training the model and the other 72 groups of data for testing.The simulation results showed that the PNN model with an optimal smoothing parameter determined by the curves of the mean square error (MSE) and the number of unrecognized probability densities (UPDs) exhibited a promising capability of predicting shrinkage of mortar. This study explored the potential of using probabilistic neural networks (PNN) to predict shrinkage of thermal insulation mortar. Probabilistic results were obtained from the PNN model with the aid of Parzen non-parametric estimator of the probability density functions (PDF) .Five variables, water-cementitious materials ratio, content of cement, fly ash, aggregate and plasticizer, were employed for input variables, while a category of 56-d shrinkage of mortar was used for the output variable. A total of 192 groups of experimental data from 64 mixtures designed using JMP7.0 software were collected, of which 120 groups of data were used for training the model and the other 72 groups of data for testing. the simulation results showed that the PNN model with an optimal smoothing parameter determined by the curves of the mean square error (MSE) and the number of unrecognized probability densities (UPDs) rendering a promising capability of predicting shrinkage of mortar.