Background:　Preterm　birth　and　small　for　gestational　age　(SGA)　are　strong　indicators　of　neonatal　adverse　outcomes.　With　the　growing　importance　of　preterm　SGA　infants,　we　aim　to　evaluate　the　prevalence　and　risk　factors　for　preterm　SGA　in　China.　Method:　We　analyzed　the　data　of　parents　and　infants　from　a　population-based　cohort　research　of　the　free　National　Pre-pregnancy　Checkups　Project　(NPCP)　in　rural　China.　Only　singleton　live　births　that　occurred　between　24　weeks　+0　days　and　36　weeks　+6　days　of　pregnancy　were　included　in　this　study.　SGA　was　defined　as　birth　weight　less　than　the　10th　percentile　of　the　reference　birth-weight-for-gestational-age　population.　A　multiple　logistic　regression　model　was　built　using　the　statistically　significant　variables　from　the　371　variables　in　the　questionnaire.　Results:　A　total　of　11,474　singleton,　preterm,　live-birth　infants　were　included.　Of　the　total　infants,　317　(2.77%)　were　preterm　SGA　infants.　A　higher　risk　of　preterm　SGA　infants　was　observed　among　mothers　who　were　on　oral　contraceptives　(OR:　8.162,　95%　CI:　1.622-41.072),　mothers　who　had　syphilis　(OR:　12.800,　95%　CI:　1.250-131.041),　and　mothers　with　a　high　eosinophil　percentage　(OR:　13.292,　95%　CI:　1.282-135.796).　Maternal　intake　of　folic　acid　at　least　3　months　before　pregnancy　(OR:　0.284,　95%　CI:　0.124-0.654)　and　paternal　intake　of　egg　and　meat　(OR:　0.097,95%　CI:0.　030-0.315)　were　protective　factors.　Compared　with　North　China,　the　incidence　of　preterm　SGA　infants　was　higher　in　South　China.　Conclusion:　Preterm　SGA　infants　were　associated　with　both　maternal　and　paternal　factors.