Abstract: To investigate the relationship between mass and closed pressure drop for tobacco rods made of different tobacco blends, the mass and the closed pressure drop of cigarette rods from 13 cigarette samples made of different single-origin tobacco leaves and 6 blended tobacco samples were analyzed by jointly using Copula function and a Gaussian mixture model (GMM). The results showed that: 1) For the majority of data, the marginal distributions of the rod mass and closed pressure drop could be fitted to symmetric normal distributions, and the joint distribution of the two could be fitted using Gaussian-Copula function. For the minority of data with abnormal values, Gaussian mixture models (GMM) could be used for identification, and then Gumbel-Copula function or Clayton-Copula function could be used for data fitting. 2) Three fundamental characteristics of an ideal tobacco rod physical model were derived, namely the space variability, the linear additivity and the reverse linear additivity of the tobacco mass. The predictive performance of the ideal mass and pressure drop physical model for tobacco rods was verified with the blended cigarettes, and the prediction accuracy was relatively acceptable. 3) The relative deviations of the open and the closed draw resistance of the finished cigarettes derived from the simplified linear grid model did not exceed 3%, which were comparable to the errors caused by batch-to-batch fluctuations in cigarette production. This study provides an algorithmic method for correlating the raw tobacco materials, primary processing and filter cigarette making processes.