The present study investigated the effect of WhatsApp on developing English paragraph writing skills of third year students enrolled at Abdallah EL Qurashy Preparatory School, Qena. Participants are (120) male and female students. The study is divided into four groups: Two experimental groups and two control groups. The two control groups are one male group (N=30) and one female group (N=30) who received traditional classroom instruction. Likewise, the two experimental groups are one male group (N=30) and one female group (N=30) and they received the treatment (WhatsApp program). Data were collected through the English Paragraph Writing Test (EPWT). Descriptive statistics, independent sample t-test and Spearman rank order coefficient of correlation were used in data analysis. Findings revealed a significant development in English Paragraph writing skills of the WhatsApp group compared with the non- WhatsApp group. Findings also indicated significant gains obtained by the experimental group in the post administration of the test as compared with the pre- administration. Furthermore, findings revealed significant gains obtained by females as compared with males. Moreover, the study concluded that WhatsApp has positive effect on developing the subjects' English paragraph writing skills (i. e., content, organization, vocabulary, mechanics, paragraph structure, paragraph format, figurative language and sensory images). Findings confirmed that WhatsApp model is an effective instructional tool that develops the students' English paragraph writing skills.

Key Words: WhatsApp, English paragraph writing skills