To establish a seed production technique for a new hybrid, tiger grouper Epinephelus fuscoguttatus×giant grouper E. lanceolatus, development of the eggs and larvae were observed. Newly ovulated eggs from a female E. fuscoguttatus of 8.2 kg in body weight were measured at 0.84±0.03 (mean±SD) mm in diameter and weighed 2,588 eggs/g. After fertilization with sperm from a male E. lanceolatus, the eggs absorbed water and acquired a spherical shape with a hard covering membrane. Each egg had an oil globule which measured 0.21±0.01 mm in diameter. The hatching started from 18-19 hours after fertilization under 28.5°C and 30 ppt salinity. The fertilization and hatching rates were 86.8% and 87.2%, respectively. The larval development was almost similar to those of the other species. Newly hatched larvae were 2.00±0.30 mm in total length and floated motionless at water surface. Larval mortality was high at early stages and stabilized from 15 days after hatched (d AH). Larvae commenced shifting habitat from pelagic to benthic at 30 d AH. One thousand seven hundred fifty three tails 30 d AH juveniles with mean total length 22.5±2.7 mm were produced from 324,000 hatched larvae.