Hello alexliu, Utilitarian means that the worth of any action is determined by it being of practical use. It is a quantitative approach to ethics and moral values. The utilitarian is characterized by being practical and functional , a rather pragmatic approach.It accepts the facts of life and favors practicality and literal truth and sees in the practical consequences the criteria of knowledge, meaning and value. Materialism on the other hand refers to a constant concern over material possessions and wealth with a little interest in ethical or spiritual matters. Matter is the only reality accordingly. Both theories share the same concept of not regarding virtues and moral ethics as a reason for happiness or satisfaction, however the difference between them is that the utilitarianism concentrates on the usefulness of action as the reason for pleasure and happiness, while the materialism sees in the possession of wealth and material belongings the main cause for joy.

Yes, I think they are different. Materialism centers conduct on the ammount of pleasure or comfort they give. It is self-centered, promoting happiness for oneself. Utilitarianism dictates that virtue is based on utility, and that conduct should be directed toward promoting the greatest happiness of the greatest number of people.