Background: Children with developmental language disorder (DLD) demonstrate deficits in vocabulary development and novel word learning processes, which have been proposed to stem from their speech perception deficits. Aims: This study had two aims. The first was to evaluate the efficacy of an intervention incorporating a computer-based phonetic training programme with rich and explicit vocabulary instruction. The second aim was to investigate the adjuvant treatment effect of phonetic training on word learning performance. Methods and procedures: The experimental group comprised 34 children with DLD aged 5-7 years, and the control group comprised another 15 children with DLD. All participants in the experimental group attended 1-h direct vocabulary instruction classes weekly for 9 weeks. They were also asked to play computer-based phonetic training games individually at home or school. Pre-post differences between groups in word definition and speech perception tasks were examined. The relationship between the experimental group's vocabulary learning performance and scores on the phonetic training games was examined using correlation analysis. Results: Between-group comparisons revealed that children in the experimental group exhibited significantly greater pre-post gains in word definition task than did the control group. Children in the experimental group performed better in the lexical tone posttest No improvement in the speech discrimination tasks was detected in the control group. Finally, correlation analyses indicated a positive relationship between the total number of phonetic games played and the pre-post gain in the word definition production task. The children's response accuracy in the lexical tone discrimination games was significantly correlated with the performance of the posttest tone discrimination task and the pre-post gain in the word definition task. Conclusions: The results of this study suggest that vocabulary intervention programmes incorporating speech perception training promote children's vocabulary and speech perception abilities. These findings can serve as evidence to support future school-based studies.