The conventional and hybrid japonica rice cultivars in Liaoning Province with three panicle types and three row distances and two hill distances were used to study the effects of physic and mechanic features,panicle factors under various row-hill spacing on the lodging resistance of japonica rice cultivars.The results showed that row and hill distances simultaneously affected the physic and mechanic features of japonica rice plant,thereby making japonica rice with different panicles exhibit different lodging capacity.Liaoyou 52210 significantly increased plant height and decreased flexural strength from 20 cm hill distance,which is the main factors of higher lodging index.Traits including plant height,the length and fresh weight of base N2 section,panicle angle,panicle length,fresh panicle weight and panicle gravity of Shendao 47 and Shendao 6 at the configuration of 25 cm×20 cm decreased significantly.At the configuration of 35 cm×15 cm,the cross-sectional area and flexural strength of the three japonica rice cultivars were significantly greater than that of others.From the perspective of panicle type,the adaptabilities of lodging resistance of Shendao 47 and Shendao 6 to the change in the configuration were better than that of Liaoyou 52210.The panicle angle of three japonica rice cultivars at the configuration of 25 cm×15 cm,30 cm×20 cm and 35 cm×20 cm was significantly larger than that of others.The fresh panicle weight,panicle length and height of panicle gravity at the later two configurations were higher as well.Generally,potential lodging and less panicles of per unit area at the configuration of high and low density limited the obtainment of high and stable yields.The flexural strength and bending moment at the configuration of 25 cm×15 cm and 35 cm×20 cm was the inducible factor increasing lodging index,indicating that both tense and sparse planting are unfavorable for lodging resistance and the flexural strength of base internode is the main target to increase the lodging resistance.The suitable bending moment of base internode should be considered when selecting cultivars with lodging resistance because the greater biomass is the guarantee for lodging resistance.