Learning motivation is the the driving force in adolescent to study diligently for reaching the good learning outcomes. This research aimed to analyze the influence of mother\u27s parenting style and sibling relationship to learning motivation of youngest child adolescent. This research was conducted in SMPN X Dramaga Bogor to sample as many as 60 youngest child adolescent (30 boys and 30 girls) aged 13-15 years. Authoritative mother\u27s parenting style, warmth, and learning motivation on youngest child adolescent girls better than youngest child adolescent boys. Mother age and birth spacing were negatively correlations with learning motivation of youngest child adolescent while, authoritarian mother\u27s parenting style, authoritative mother\u27s parenting style, warmth and relative power were positively correlations with learning motivation of youngest child adolescent. Learning motivation influenced by mother age, authoritative mother\u27s parenting style, relative power, and conflict
