The present research investigates the causal influence of phonological awareness and oral language proficiency on beginning reading and spelling development of Chinese kindergarteners learning English-as-a-second-language (ESL). Three inter-related studies using correlational and intervention design were conducted to examine (1) the role of phonological awareness in English reading and spelling; (2), the contribution of oral language proficiency to English reading and spelling; (3), the efficacy of the phonological awareness instruction led by kindergarten teachers in classroom settings, and (4) the cross-language associations of metalinguistic skills and reading between English and Chinese. In Study 1, 50 children from two Hong Kong ESL kindergartens were assessed on measures of general intelligence, English and Chinese phonological awareness, English and Chinese oral language proficiency, and English word reading. With age and general intelligence statistically controlled, both English oral language proficiency and English phonological awareness (phoneme awareness) accounted for unique additional variance in English word reading. In Study 2, the effects of phonological awareness instruction were examined on 59 children from two local kindergartens. The phonological awareness instruction, which taught syllable awareness and rhyme awareness, was compared to a treated control group. The instructional programme was able to enhance phonological awareness skills at the rhyme level but not at the syllable level. Word reading was not significantly different between the instructional group and the comparison group during the posttest. The results suggest that instructional programme that solely focuses on phonological awareness skills might not be able to enhance reading skills of Hong Kong Chinese ESL children. Study 3 investigated the effects of a 12-week language-enriched phonological awareness instruction on 76 Hong Kong young ESL kindergarteners. The children were randomly assigned to receive the instruction on phonological awareness skills embedded in vocabulary learning activities or a comparison instruction which consisted of vocabulary learning and writing tasks but no direct instruction in phonological awareness skills. They were tested on oral language skills, phonological awareness at varied levels, reading, and spelling in English before and after the program implementation. The results indicated that children who received the phonological awareness instruction performed significantly better than the comparison group on English word reading, spelling, phonological awareness at all levels and expressive vocabulary on the posttest. In addition, regression analyses on both pretest and posttest data showed that phonological awareness (phoneme awareness) and oral language proficiency (expressive vocabulary) are significant predictors of English reading and spelling. Cross-language transfers of phonological awareness were found. The present research suggests that both phonological awareness, particularly phoneme awareness, and oral language proficiency (expressive vocabulary) play a causal influence on English reading and spelling among Chinese ESL children. The efficacious language-enriched phonological awareness instruction indicates that kindergarten teachers with sufficient training and support are able to implement instruction that aims to teach phonological awareness directly and explicitly. The significant cross-language associations suggest that phonological sensitivity is a common competence that children need to acquire in learning to read two writing systems. / published_or_final_version / Education / Doctoral / Doctor of Education