The research result on density and amount of basal fertilizers for breeding garden on two cold resistant rubber varieties VNg 77-2 and VNg 77-4 was found that the density of 20,000 trees/hectare given highest number of effective grafts, higher than control treatment (25,000 trees/ha) from 23.9 to 33.4 percent. The number of grafts in two treatments of basal fertilizers (30 tons/ha and 35 tons/ha) was similar, and they are significantly higher than the control (20 tons/ha). The increased amount of grafts was different between two varieties the result showed that the higher rate was found in variety VNg 77-4 (30.3-33.9 percent) while VNg 77-2 has only 26.5-30 percent increasing. There was not significant different between the amount of 25 tons/ha and the control 20 tons/ha.