The present study aimed at developing English language planning strategy of second year distinguished governmental language preparatory school pupils using the a WebQuest model. Fifty participants from second year at Hassan Abu- Bakr Distinguished Governmental Language School at Al-Qanater Al-Khairia (Qalubia Governorate) were randomly assigned into two groups: experimental group (N=25) and control group (N=25). Two main instruments were used: writing strategies questionnaire and think-aloud protocol. The instruments were administered before and after the experiment. Quantitative and qualitative data analyses were conducted. T-test was used to compare the mean scores of the control group and the experimental one in the pre-post applications. Results showed that the experimental group pupils have developed their English language planning strategy. It was concluded that the WebQuest model was effective in developing English language planning strategy of the participants. It was also recommended that the WebQuest model should be integrated into writing instruction programmes.