Currently, the average grain corn yield in farmer fields is 3–4 t/ha and sometimes as low as 1 to 2 t/ha. Whereas large scale planting in the research station, the harvested average yield can reach up to 5 to 6 t/ha and CCT yield of 8–9 t/ha, and the operation cost is more than RM 5,000.00/ha. The planting spacing study is one of the mechanisms for lowering the cost of grain corn cultivation. It also plays a vital role in the growth of corn crops. This study aims to evaluate the effects of planting spacing on the yield of grain corn. The evaluation has been conducted at MARDI Seberang Perai, Pulau Pinang. A 90hp tractor is attached with a pneumatic row planting machine used for the cultivation operation. Five planting spacing (13, 16, 19, 22, and 25 cm) were evaluated. The study showed no significant differences in growth performance and cob corn. For the yield, the results showed significant differences at p < 0.05. The highest yield at planting spacing at 13 cm is 10.78 tan/ha.