This dissertation studies the acquisition of Mandarin relative clauses (RCs), including the distributional pattern of different RC types in adult child-directed speech (study 1) and four-year-old Mandarin-speaking children's comprehension of different RC types (study 2). An RC is a subordinate clause that modifies a noun and is embedded within a noun phrase (e.g., "The cat that hits the dog"). Two major types of RCs have received much attention in the literature, subject-extracted RCs (SRCs) and object-extracted RCs (ORCs), and previous studies have found that having an animate versus an inanimate head noun affected the relative difficulty of SRCs and ORCs. This dissertation focuses on Mandarin RCs under the animacy constraint, and the results are discussed to evaluate theories that are used to account for RC acquisition. Study 1 analyzes the distributional pattern of four Mandarin RC types (SRC-animate; SRC-inanimate; ORC-animate; ORC-inanimate) in written texts (Mandarin story books) and adult child-directed speech extracted from the Child Language Data Exchange System (CHILDES). As frequency effects could occur at the level of the target structure and/or its related structures, the corpus analysis was conducted on both genuine RCs and RC-like structures. The results showed that the distributional frequency of SRC versus ORC differed based on the level of analysis. When focusing on genuine RCs, SRCs occur more frequently than ORCs when the head noun is animate; whereas ORCs occur more frequently than SRCs when the head noun is inanimate. When analyzing RC-like structures, SRC-like structures occur more frequently than ORC-like structures regardless of the head noun animacy. Study 2 examines four-year-old Mandarin-speaking children's comprehension of SRCs and ORCs with animate and inanimate head nouns. Children's comprehension was evaluated using a picture-referent selection task. The results showed that children performed significantly better on SRCs than ORCs in both animacy conditions, which supported the predictions made by the relativized minimality theory (Friedmann et al., 2009; Rizzi, 1990) and rejected the dependency locality theory (Gibson, 1998; 2000). Furthermore, the results supported the experience-based theory (e.g., Ambridge et al., 2015; Diessel, 2007) on the level of surface structure (but not target structure) distribution: children's comprehension pattern aligns with the distribution of RC-like, but not genuine RC, sentences. To sum up, in the current dissertation, study 1 adds corpora evidence (both written and spoken) to the literature regarding Mandarin SRC/ORC distribution under the animacy constraint. Study 2 contributes additional data to the Mandarin SRC/ORC asymmetry literature and provides support to an SRC over ORC advantage. In addition, this dissertation provides cross-linguistic evaluation of the language acquisition theories based on evidence from Mandarin, a language that is typologically different from the most studied Indo-European languages. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]