Qinghai is a multinational province. Among the minority nationalities, Tibetan has the largest population and the widest inhabit region. They mainly live in the 6 following autonomous prefectures: Hainan, Haibei, Huangnan, Yushu, Guoluo and Haixi. Yushu prefecture of Qinghai Province is the largest education prefecture among the six autonomous prefectures. In2018, there were 109029 students in the prefecture, and ethnic minorities accounted for 98.8% of the total registered population of the prefecture.2      

In this research, PPVT-5 and image naming tools were used to study the bilingual semantic development of Tibetan children in Yushu prefecture, and the influence of home  language use on the semantic development of Tibetan bilingual children in home literacy environment.In order to understand the semantic development of Tibetan preschool children in bilingual or trilingual environment, this study uses a hybrid design, which is, a combination of horizontal and vertical methods to test children’s semantic expression and understanding.It is hoped that through horizontal comparison, we can understand the similarities and differences of semantic development between monolingual and bilingual children. At the same time, through vertical research, we can understand the development and changes of bilingual semantic of Tibetan urban and rural bilingual children, furthermore analyze the correlation between bilingual semantics of children and home literacy environment and home language use, so as to explore the bilingual semantic development of Tibetan children and the influencing factors of language environment.In this study, 152 Tibetan children and 56 Han children from four kindergartens in Yushu were tested in two stages. Research data from 152 families of literacy environment and home language use were collected by questionnaire. 

The research shows that:①With one year's bilingual education in kindergartens, Tibetan urban and rural children’s comprehension semantics of Tibetan and Mandarin show a good development trend after they have entered bilingual kindergartens. Moreover there is no significant difference in the development of bilingual semantics between different genders.There are differences in the development of Tibetan and Mandarin bilingual semantics between urban and rural children.When urban children enter the kindergarten, the comprehension semantics and expressive semantics of Mandarin are better than that of Tibetan. This gap increases with age.The development level of Tibetan expressive semantics is better than that of Mandarin expressive semantics when rural children first enter the kindergarten. Tibetan semantic development is no longer dominant with age. In other words, children tend to show that their Mandarin semantic development is better than Tibetan semantic development.The development level of expressiveness and comprehension of Tibetan children in urban areas is lower than that of Han children in Mandarin as a whole. When Tibetan children enter the kindergarten, the development level of comprehensiveness and expressiveness is lower than that of Han children of the same age group. The development level of comprehensiveness and expressiveness after 6 is the same as that of Han children. Nevertheless, the development level of expressiveness still has significant difference with age.②There are great differences in Tibetan home language use. Urban parents prefer using Tibetan language talking with their children (subjects), while children prefer bilingual language to talk back with parents. The frequency of Tibetan and Mandarin used in communication between brothers and sisters is almost the same. When children talk to their friends outside, they are more inclined to use Mandarin. The language use among the rural family members is more inclined to Tibetan, and the language preference among the members is basically the same. When children talk to their friends outside, they tend to use bilingualism.③There is a significant positive correlation between Tibetan children's home literacy environment and home language use. Moreover, a significant positive correlation between home literacy environment and home language use and Mandarin semantic development. Nevertheless, there is a negative correlation between home literacy environment, home language use and Tibetan expressive semantic development. Among the data, the negative correlation between home language use and Tibetan expressive semantic development is the highest.Home language use can significantly predict the development level of Tibetan children's Mandarin semantic and Tibetan expressive semantic. Home language use can significantly promote the development of Mandarin expressive semantic, but it does not play a role in promoting the development of Tibetan expressive semantic .

There is still a lot of room to improve the semantic development of Tibetan and Mandarin for children. We need to think about the quality of bilingual environment in families and kindergartens, in order to improve the quality of Tibetan and Mandarin bilingual home literacy environment, and create a bilingual language environment for children. Parents should try to communicate with children in either standard Mandarin or pure Tibetan language, and avoid using mixed language (Tibetan and Chinese mixed).At the same time, we should improve the quality of bilingual language environment in kindergartens, strengthen the bilingual education ability of front-line teachers, and formulate the training plan for improving the ability of local bilingual teachers in accordance with the “Implementation Guide for StandardizedTraining of New Kindergarten Teachers” newly issued by the State Council.