There was a association between malnutrition and related factor: the birth weight of infants under 2500gr (OR=6.13; 95% CI: 1.27 - 21.34; p=0.014); educational level of mothers (OR=4.86; 95% CI: 1.05 - 19.14; p=0.039); weaning time under 18 months old (OR=3.62; 95% CI: 1.21 - 9.46; p=0.022); trẻ không được ăn bổ sung khi tròn 6 tháng tuổi (OR=3.28; 95% CI: 1.09 - 9.27; p=0.009); the children who had diarrhoea (OR=2.65; 95% CI: 1.07 - 8.22; p=0.042).