When I want to describe my self .. Should I say I'm a graduate or graduated student in .. What is more accurate ? Past or present ? P.s: I have a bachelor degree and I'm not planning currently to have a master.
Well, if you're not a student anymore, you probably shouldn't be referring to yourself as a student at all, and just say that you "graduated with a bachelor's degree in ...". If you're an engineer or architect, you could say something more along the lines of "I'm an engineer / architect, and I received my undergraduate degree from ...".
However, the word to use would be "graduated", because (as you appear to have correctly surmised) a "graduate student" is a person in graduate school (so, a master's or doctoral student).
Well, just off the cuff, I can't think of a situation where it would not sound wrong or stilted to refer to myself in past tense as a "graduated student" in/of... If you are a "graduated" student, you are a graduate, and so would use the present tense. Even when filling out a resume, for example, and actually listing your past achievements, you would still never use the term "student." You should stay in the present: I have my BS degree from____; or, I'm a graduate of____; or, I graduated from____.