Objective To explore the influencing factors in family associated with language development delay (LDD) of toddlers, in order to provide evidence for early intervention of LDD. Methods A total of 55 children aged 16 to 30 months and diagnosed with LDD in Peking Union Hospital from July 28th, 2020 to January 27th, 2021 were enrolled in this study.Meanwhile, 71 typical developed children who took physical examination in this hospital were selected as control group.Children's language development was identified by Chinese Communicative Development Inventory-Putonghua version (CCDI-P).The correlations of language development with educational level of parents and main caregivers, family environment, birth status were analyzed. Results There was no difference on domestic dialect between the two groups (P>0.05).Compared with control group, LDD group had less toddlers from only-child family, less parents or main caregiver with bachelor or higher educational degree, more introverted caregivers, more grandfather or nanny as the main caregiver, longer screen time and earlier exposure to screen, more proportion of parental company <2 h/d, screen time ≥2 h/d and being exposed to screen <12 months old(P<0.05).Logistic regression analysis revealed that the onset age for screen ≤12 months old(OR=9.562, 95%CI:3.106-29.437), screen time≥2 h/d(OR=3.222,95%CI:1.169-8.884) and grandfather or nanny as the main caregivers (OR=7.034,95%CI:1.930-25.634) were the risk factors for LDD of toddlers(P<0.05). Conclusions Besides being exposed to screen too early or too long, grandfather or nanny as the main caregiver is the home environmental risk factor associated with language development delay in toddlers.So it is supposed to avoid early screen exposure, to reduce the screen time, and to encourage parents to take care of their children personally.