The aim of this research was to know the effectiveness of Word Web to teach vocabulary at the second grade students of SMP PGRI Gumelar in academic year 2013/2014.This research was experimental one of which, the subject was 56 students who were divided into two classes. The first class the VIII C 28 students was the experimental class in which Word Web was implemented to teach English vocabulary and the second class the VIII A with 28 students, was the control class. To collect the data, pre-test and post test were used to find out the effect of the treatment that given to the experimental and control class. The test was given in the form of objective test, especially multiple choices. In analyzing the data, t-test was used to find out the effect of the treatment.
Based on the computation, the result of t-test was 3.784 while the value of t-table was 1.674 with df=54. This means that the result of t-test was higher than the value of t-table (3.784> 1.674) which showed that hypothesis made was acceptable. Thus, it can be said that Word Web was effective to teach English vocabulary.