The reconstituted tobacco paper base with different ratios was determined by X-ray grammage instrument. The effect of tube voltage on repeatability，sensitivity and detection limit of the instrument was analyzed.The results show that tube voltage 6 000 V is more suitable for the determination about the grammage of the reconstituted tobacco paper base;and it is found that the grammage indication value has a high linear relationship with the grammage measured value about the reconstituted tobacco paper base with different ratios，and the established linear regression model with determination coefficient over 0.99，and the predicted maximum relative deviation less than 1%. The reconstituted tobacco paper base with different content of calcium carbonate has great influence on the establishment of the model.The reconstituted reconstituted tobacco paper base containing different content of tobacco stem and tobacco powder ratio and external fiber wood pulp has relatively little influence on the establishment of the model.