In Chapter 5 of Frankenstein, what does Victor's dream comment on?
Is that means Taboo? I think when he kisses Elizabeth then it changes to be his mother in his dream.. he feel guilty of doing some thing wrong. is that because he feels guilty of making a monster? that why even in his dream he feels that he does wrong thing by kissing on his mom's lips.
I agree with your interpretation to some extent, but I think of this dream a little differently too.
I think the dream is telling us two things. First, as you say, it shows his guilt over creating the monster. I think that this is why he dreams such horrible things.
But I think the dream is also serving another purpose. It is foreshadowing for us what the impact of Victor's actions will be. The monster that he has just created will kill so many things that Victor loves. I think these are represented by Elizabeth (and this actually foreshadows her real death) and his mother. They are both people who Victor loves or has loved. They represent the people the monster will kill.
There are many ways to interpret Frankenstein's dream. One way is to understand it as a kind of foreshadowing, not just of Elizabeth's death, but of how the creature will persecute Frankenstein for the rest of the novel. Another way to think about the dream is that it suggests the essential unnaturalness of Frankenstein's creation, and Frankenstein's identity as its "mother." The confusion in the dream, which begins with a sexual image (Frankenstein kissing Elizabeth on the lips) but ends with Elizabeth, in the act of the kiss, transforming into the corpse of Frankenstein's mother, suggests that Frankenstein's work undermines not simply his relationship with his fiance, but also what it means to be "male" or "female." It has been remarked that Frankenstein is a book about what happens when a man decides to have a child without a woman, and I think the dream, in which desire (for Elizabeth, or for knowledge) is transformed into death and decay, is a graphic representation of how the monster's creation undermines or betrays "normal" family relations.
When Frankenstein wakes up, it is as if the dream continues. The monster is there, looking at him. The monster's smile is another kind of perversion, like the smile of an infant made grotesque. Frankenstein is horrified, and flees; it is like he is a mother who is abandoning their child. Had Frankenstein been able to love his creation, how much horror could have been avoided?