From Chemical Engineering undergrad to chemistry graduate school Right now I'm studying Chemical Engineering My CGPA is 3.4 and I'm a junior.
I'm thinking about joining a chemistry graduate program after a graduate.

So my question is if I applied will they look at my chemical engineering core GPA or only science subjects GPA?

and as an international student if my CGPA was around 3.5 where can i apply in USA, CANADA , UK ? 

THANKS
I am a Canadian graduate student in Applied Science with an undergraduate in Engineering so my answer comes from some personal experience.

What I've always been told is that your grades from relevant courses in the most recent two years of university are the most important when considering you for acceptance into a program. So if you apply for a BSc in Chemistry, your Chemical engineering courses should be considered relevant, but any non-technical electives would not.

In most Canadian graduate schools you are expected to maintain an average above B+ (3.3 out of 4.3 maximum). Depending on the scale used to determine your CGPA you might be just above that threshold, which makes your GPA respectable but not stellar. 

You can apply to any university you like, they won't turn away your application. Make sure to check out the U15 Universities if you plan on applying in Canada. They are generally considered the most respected universities in the country.

If you have any co-op work terms/summer terms remaining before you graduate, and if you are a student at a Canadian university, you should consider applying for an NSERC Undergraduate Student Research Award. This will get you some research experience in your undergrad that will help you stand out on a grad school application regardless of your GPA.