The research of bilingual is a hot topic in the cognitive and psycholinguistic fields. It mainly focused on the representation of two languages. Three theories have been proposed to explain the mechanism of two languages’ lexical and semantic representations. Potter et al. (1984) put forth the Word Association Hypothesis and the Concept Mediation Hypothesis. The former suggests that the L1 and the L2 are connected at the lexical level and that only the L1 has access to conceptual representation. The later suggests that both L1 and L2 have independent access to a common conceptual representation, but there are no direct inter-connections between their lexical representations. Kroll and Stewart (1994) proposed the Revised Hierarchical Model which suggests that lexical connections are formed between the two languages, and their lexical representations are both directly connected with a shared conceptual representation. But the strength of links was not equal. The link of lexical representation from L2 to L1 is stronger than that from L1 to L2, and stronger direct links are established between the L2 and the conceptual store as a bilingual becomes more fluent in the L2. Though many data of bilingual researches supported the Revised Hierarchical Model, it’s not concluded how the lexical representation of L2 accesses its conceptual representation. Furthermore most of the evidences were collected from national bilinguals but not diglossia speakers. So we aimed to study the accessing process of two languages of proficient Teochew-Mandarin bilinguals with semantic decision task, and also to test which hypothesis of above are more reasonable. Using cross-language priming paradigm and semantic category judgment tasks, two experiments were designed to examine how the lexical representations of two languages access its conceptual representation under the conditions of inner-auditory and auditory-visual channel. All participants who came from Chaozhou were proficient Teochew-Mandarin bilinguals and their native language(L1) was Teochew. Participants were required to judge whether the target words were food-word or not. Stimuli included 48 Teochew words and 48 Putonghua words, half of which were Teochew- Putonghua pair words of high semantic correlation and the others were of low semantic correlation. Reaction times for correct responses and correct rates were analyzed with repeated ANOVA by subject and by item. In experiment 1, there were significant priming effects from L1 to L2 under the presentation conditions of auditory-auditory channel(43ms) and auditory-visual channel(24ms). In experiment 2, there were also significant priming effects from L2 to L1 under the two conditions(39ms and 79ms). In the presentation condition of auditory-auditory channel, there was no difference between the amounts of cross-language priming effect. Yet in the condition of auditory-visual channel, the amount of priming effect from L2 to L1 was significantly more than that from L1 to L2. The results suggested that proficient Teochew -Mandarin bilinguals shared a same conceptual representation while each had independent lexical representation with correlation. The lexical representation of L1 and L2 both could access to semantic representation directly, but the link strength between lexical representation and semantic representation of the two languages were still asymmetric in different sensory channels. All the findings supported the Revised Hierarchical Model.