We evaluated the effectiveness of a mobile phone text-messaging based smoking cessation intervention package among Chinese adolescent smokers. Students aged 16-19 years were recruited from six vocational high schools located in Shanghai. We assigned the six schools to an intervention group or a control group by cluster randomization. The 92 participants in the intervention group were given tailored information via mobile phone text-messaging for 12 weeks. The 87 participants in the control group were provided with a self-help pamphlet about smoking cessation instead. After the intervention, attitudes towards the disadvantages of smoking were significantly improved, and the level of nicotine dependence and cigarette dependence significantly decreased in the intervention group. The intervention group had a relatively higher self-reported 7-day abstinence compared to the control group and 30-day abstinence, but the differences were not significant. However, the intervention group had a significantly higher rate of smoking reduction (66% vs. 35%) and moving forward in quitting stages (52% vs. 18%) compared to the control group. The interactive and tailored assistance provided by the mobile phone text-messaging was effective in smoking behaviour intervention in Chinese adolescent smokers.