Abstract: Low tar content tobacco production is one of the important directions in the development of flue-cured tobacco. It is of significance to research the appropriate key cultivation techniques of low tar content tobacco in Northeast China, which is the biggest planting areas of filling type low tar content tobacco in China. In this study the influences of nitrogen application, potassium application, remained leaf number and spacing in the rows on tar content and intrinsic physical and chemical indexes were investigated with quadratic orthogonal regression design in Liaoning and Jilin provinces. The results showed that the effects of the four factors on tar content were in the order of spacing in the rows> remained leaf number> nitrogen application≈ potassium application. The optimal treatments for low tar were nitrogen application, potassium application, remained leaf number and spacing in the rows being 4.50, 20.08 kg/667m², 15 leaves and 0.40 m in Liaoning, and 3.99, 18.10 kg/667m², 20 leaves and 0.33 m in Jilin respectively. Comparing with current production control, the better treatment combinations were that nitrogen application was decreased by 0.5 kg/667m², potassium and nitrogen ratio was up 0.5, remained leaf number was increased by 2, and spacing in the rows was reduced about 0.15 m. Furthermore, the main effect on total alkaloid content and K₂O content were from nitrogen application and potassium application respectively in Liaoning, and the average leaf width was impacted mainly by the spacing in the rows. In Northeast China, low tar tobacco production should be based on population quality control, and the second was the regulation of nutrient management. In addition, the lower total alkaloid content and the higher potassium content in Liaoning and the smaller leaf width in Jilin could be used as the reference index for low tar content tobacco. It is suggested that the combinatorial techniques should be further validated and then to be utilized in Northeast China. The physiological mechanism of low tar content tobacco formation should be also further studied.