This book is the outcome of the project which was undertaken to analyze the factors affecting Consumer behaviour towards online purchasing of gifts; a comparison between generation X and Y, Sri Lanka. This research study carries outs to measure the level of purchasing decision making for online gift buying in Sri Lanka comparing between generation X consumers and Generation Y consumers. The research was conducted by using the Likert scale questionnaire measuring five variables of Psychological factors, social factors, cultural factors and the purchasing decision of the consumers. This was conducted with the 553 consumers, while 242 consumers were from Generation X and 311 consumers were from generation Y. It was revealed that, for generation Xers psychological factors as in related with the interest and knowledge plays the highest role while for Generation Y, the cultural and social characteristics have a similar effect. As a final recommendation, raising the purchasing frequencyof the clients isn't easy when it comes to developing a service conducted via online even with generation Y. Therefore it needs to be properly incorporated and developed.