This dissertation consists of two studies, which respectively investigate L2 Chinese learners' acquisition of simple wh-questions of different grammatical functions longitudinally over their first-year learning and their acquisition of indirect questions and wh-questions in complements at the end of their first year. The participants consisted of 21 first-year English-speaking learners of Chinese. Both grammaticality judgment (GJ) and oral production (OP) tests were used. Study 1 reports that only attributive wh-questions posed more difficulty to the participants than object wh-questions in OP test at the beginning stage, and adverbial wh-questions and object wh-questions were not found to be significantly different to the participants as reported in some L1 and L2 studies. This author attributed this to the different syntactic mechanism that L2 learners of movement language and learners of in-situ language go through. The initial stage of participants' grammar did not display a clear presence of [+wh] feature strength, and the development of the [-wh] feature strength in learners' L2 grammar was not linear, but U-shaped. Study 2 reveals that learners' performance on indirect questions and wh-questions in object complements was not as good as their performance on simple wh-questions at the end of first year learning. For indirect questions, the initial stage of participants' L2 grammar showed an obvious L1 influence, the embedded [+wh]. For wh-questions in complements, it did not show an L1 influence, the matrix [+wh], but an embedded [+wh], which is non-target like but resembles wide-scope wh-questions with an embedded [+wh] in Malay and Madurese. Learners' performance on simple wh-questions patterned together with that in matrix clauses of wh-questions in complements, which was better than their performance on embedded clauses of the two types of complex wh-questions. Evidence for connection between their performance on simple wh-questions and matrix clauses of wh-questions in complements regarding the grammatical feature that wh-words are not allowed in clause initial position was revealed, but there was no strong evidence for connection between their performance on embedded clauses of the two types of complex wh-questions. It suggests that learners might be using different strategies for acquisition of structures of different natures.