Passivization has complex structures across different languages. It is well-known that the syntactic operation in the English passive construction and the Cantonese passive construction is different. When learning the English passive construction, Cantonese-speaking secondary school students of Macao tend to find difficulties and make non-target-like productions. This paper investigates the acquisition of the English passive construction by Cantonese-speaking Secondary School students in Macao. The patterns of non-target-like productions by Cantonese-speaking secondary school students of Macao and explanation of the phenomenon found constitute another research focus. The participants (N=90) were secondary school learners from Junior 3 to Senior 2 of a Chinese-medium middle school (Pooi To Middle School) in Macao. Three tasks, namely the grammaticality judgment task, translation task and describing changes, were used to elicit data from the learners. With the research design of the three tasks, the Cantonese EFL learners‟ sensitivity to different English passive constructions and their mastery of the English passive constructions are investigated. In addition, students‟ competence in using correct subject-verb agreement, past participles and identifying the patient noun phrase as the subject is also analyzed. Results show that the correction rate of the three tasks was gradually increasing when learners‟ academic levels increased. The study shows that Cantonese ii secondary students in Macao had the basic understanding of the formation of English passives in that they were aware that English passives are formed by BE and the past participle of the main verb. However, these learners had some difficulty in applying the appropriate past participle and the correct form of BE. Moreover, some students mistreated intransitive verbs as transitive verbs and the correction rate of infinitival passives was relatively low. Overall, this study demonstrates that the Cantonese students‟ acquisition of the English passive construction is not merely influenced by their L1. More importantly, the salient overgeneralization shown in overregulating irregular verbs and excessively mischaracterizing intransitive verbs, as we ll as the overuse of present participles for past participles, seems to support the Interlanguage Hypothesis in second language acquisition as these intralingual and developmental errors do not originate in the students‟ L1.