The objectives of this research were to investigate the system of rice intensification (SRI) on early growth, grain yield, and yield components under Chinese milk vetch residue-mulched no-tillage cropping systems at silt loam soil. The field was prepared as a split-plot design with three replications, main plots consisted of Dongjinbyeo, and Sobibyeo as a cultivar, and subplots consisted of $10{ imes}10$ cm, $20{ imes}20$ cm, and $30{ imes}30$ cm as a planting density. Weed infestation during rice growing season was more severe in wider planting density $30{ imes}30$ at 35 days after transplanting (DAT), and $20{ imes}20$ cm at 95 DAT in both Sobibyeo and Dongjinbyeo. The maximum plant height was recorded in Sobibyeo compared with Dongjinbyeo, $10{ imes}10$ cm and $20{ imes}20$ cm planting density compared with $30{ imes}30$ cm from 20 DAT until 60 DAT. Among the three planting densities, SPAD values were significantly greater in planting density of $20{ imes}20$ cm both in Sobibyeo and Dongjinbyeo followed by $30{ imes}30$ cm compared with closer planting density of $10{ imes}10$ cm. The lowest grain yield was observed in wider planting density of $30{ imes}30$ in both Sobibyeo and Dongjinbyeo due to lower number of panicle per unit area. Our findings suggest that optimum planting density for SRI in no-tillage paddy was $20{ imes}20$ cm and it should be useful the systems to small-scale rice farmers in Korea as a sustainable farming system.