To accuse someone of something means that you state that they have done something wrong. It is usually something that is clearly understood as illegally wrong or is unkind or unpleasant to another person. He was accused of lying. They accused him of stealing. To blame someone for something means to state that a person or thing is responsible for a bad thing happening or did something wrong. The high winds are to blame for the widespread power cuts. I blame you for making me miss the bus. (i.e. it's your fault) I hope this helps.