The main purpose of this study is to find out what teaching method is more effective than others through experiments for college students. Therefore, this study aims to review various effective methods of vocabulary teaching. According to the results of the experiments, the methods of teaching vocabulary through the process of word formation and meaningful words led to the high scores at the posttest regardless of the scores gained by the individual subjects at the pretest. However, the method of teaching vocabulary through context showed that the improved scores at the posttest generally reflected the individual differences of the scores at the pretest. That is, in the latter, it is recognizable that the subjects who achieved the high scores at the pretest did very well at the posttest as well. In conclusion, judging from the mean rate of improvement, the method of teaching vocabulary through word formation seems to be more effective than that of teaching vocabulary through meaningful words and context.