The objective of this research is to investigate the effectiveness of Zip Zap Gamein developing speaking skill of the seventh grade students at SMP Negeri 3 Palu.This research applied quasi-experimental research design by involving anexperimental group and a control group. The population of the research is theseventh grade students of SMP Negeri 3 Palu. The sample is taken by applyingpurposive sampling technique. The sample is 30 students of VII A as theexperimental group and 29 students of VII D as the control group. Thetechnique in collecting data is test, pretest and posttest. Pretest is applied beforetreatment while posttest is applied after treatment. The treatment is given foreight meetings. The data were analyzed statistically in order to know thesignificant difference of students' speaking skill in pretest and posttest. Byapplying 0.05 level of significance and 57 degree of freedom (30+29-2= 57), itis found that t-counted value (6,52) is greater than t-table value (2.003). Itmeans that the hypothesis is accepted. In conclusion, Zip Zap Game can developthe speaking skill of the seventh grade students.