Abstract:The sample data was from dahurian larch (Larix gmelinii(Rupr.)Rupr.) plantations located in Daqingchuan and Yongcui Forest Farms, Dailing Forest Bureau in Heilongjiang Province. Height-diameter model with stand variables was developed based on sample data from 41 plots and Richards’s model. A mixed-effect modeling approach was applied in fitting Richards’s model yij=(β1+bi1)(1-e-(β2+bi2)xij)(β3+bi3)+εij and the same model with stand variables yij=(β1+bi1)(Dq)(β2+bi2)(1-e-(β3+bi3)(N(β4+bi4))xij)+εij. Results showed that Richards model with inclusion of random parameters b1, b2 was the best when fitting mixed-effects model of Richards; Inclusion of random parameters b2, b4 was the best when fitting Richards model with stand variables. Model validation indicated that mixed model showed lower error than fixed-effects model when randomly selected independent samples. However, using calibration with randomly selected four trees, mixed model reduced the bias and RMSE of the prediction by almost 71.8% and 42.1%, respectively.