Abstract: This forage sorghum experiment was carried out at the Experimental Farm, Faculty of Agriculture, Khon Kaen University, Northeast Thailand to investigate effects due to N-K2O rates and different planting distances. The experiment was laid out in a 3x4 factorial arranged in a Randomised Complete Block Design with four replications and consisted of twelve treatment combinations (3 rates of N-K2O and 4 planting distances). The results showed that an increase in N-K2O rates significantly increased most growth parameters of the sorghum plants. Whilst an increase in planting distances significantly increased stem and leaf dry weight/plant but decreased Leaf Area Index (LAI). Dry weight/plant of lower dead leaves was not affected by either N-K2O rates or planting distances. The highest LAI value only reached 5. An increase in N-K2O rates did not affect crop growth rate (CGR), whilst an increase in planting distances significantly decreased CGR. Leaf area duration (D) significantly increased with an increase in N-K2O rates. Brix value significantly increased, but only at the highest rate of N-K2O. Seed head and seed yield significantly increased with an increase in N-K2O rate, but the reverse was found with an increase in planting distances. The highest total dry weight and seed yield were found with the highest rate of N-K2O (650-100 kg ha-1) and the narrowest planting distance (50x10 cm). Total dry weight and seed yield were positively correlated to D. The highest Crude Protein (CP) was found with the highest rate of N-K2O and the widest planting distance (50x25 cm). Neutral Detergent Fibre (NDF) was not affected by either N-K2O rates or planting distance, but Acid Detergent Fibre (ADF) was significantly affected by planting distance. Dry Matter Degradability (DMD) was not significantly affected by N-K2O rates, yet planting distance did have a significant effect on DMD.