The dominant measurement theories were briefly reviewed at the begin-niug of this paper. Although many of these measurement theories have a great amount of similarity, each and every theory still has it's own unique part. Aud none of them was completely built on the bases of reasonable model assump-tions and solid theoretical derivation according to mathematical statistics, This phenomenon motivate the research for a new statistical model which can integrate those dominant measurement theories, This paper present a new measurement model which is inteuded to fulfill the object. In order to eval-uate how well does the new measurement model achieve the object, a set of criteria were also presented. The structure of the new measurement model is composed of the charae-ters of subject, item, and scoring rule. All model assumptions were obviously pointed out, and the reason of their existence were also Shown, The new measurement model was summarized in a list of eight model assumptions. Because the method of maximum likelihood estimation and the method of moments were inappropriate for this case, the method of least squares esti-mation was emploied to get the estimators of unknown parameters, Throught a tedious dervation, the dose-form solution of LSE were found and presented in the paper. The result of investigating the statistical properties of estimators was also presented in the paper. With the normality assumption on measurement error, It was shown that MLE is identical to LSE. Then, the unbiased estimator of ability parameter Was shown, The standard error of ability parameter estimator was also Shown to be the minimum one. The distrihution of ICC estimator was Shown to be an uniform distribution. In order to prompt the readers of the paper to evaluate how well does the new measurement model achieve it's object, the criteria for evaluation was presented again in the conclusion the paper. Based on the theoretical aspect, the new measnrement model indeed contains all functions covered by those existing and dominant models all doesn't inherit the defect of those models. Although the new measurement model is so powerful that it can be treated as the genernal model of those existing and dominant models, it should be applied with eantion until a series of tryouts have been successfully carried out. Then, it is the time that the new measurement model can bring an unification to those controversial models.