Is the sentence okay?

I'm afraid I don't understand what meaning you're trying to convey, so I would not consider this sentence to be "OK."

Is it technically a "sentence" at all?

Thank you both.

Me too didn't think it was a sentence either.

What the "sentence" intended to convey is:

Study well and make progress everyday.

Can we convey it as:

Good good study, up up everyday?

Why use this form of expression? The purpose is to rhyme with its original Chinese.

It has a noun and a verb; must be a sentence. LOL

Can you translate that for us?

I wonder whether the word "up" there is offensive.

No. (Why?) But, OristarA, I have to tell you that even for very skilled expert native speakers, creating catchy slogans that "work" well is considered very difficult indeed, and people that have this ability often get well paid jobs with advertising agencies. Your slogans: "Good good study，day day up." and "Good good study, up up everyday" have, to this native speaker, a very strong air of having been produced by either a foreigner in the first stages of learning English, or a child. Note that "everyday" means "ordinary, not special" whereas if you wish to convey the meaning of "each day", you write "every day" (2 words).

Also I feel that your requirement for your slogan to "rhyme with the original Chinese" is mistaken. Successful language learning requires that you let go of the familiar native language and its crutches. You will never be a good swimmer if you always hold on to the side of the pool.

Thank you Contrex.

So "Good good study, up up every day" is acceptable and not childish?

What do you mean "acceptable"? To a native speaker (this one) it is almost meaningless, and quite irritating. How about:

"Unlike the Great Wall Of China, which will stand for ever, the great wall of English will be broken down brick by brick by the valiant efforts of our class."

This illustrates that direct translations rarely work out well, Ori.

Having said that, it is a possibility in the sense that people in English sometimes use this type of repetitiveness to make a point.

Not necessarily childish, but improper English grammar.

It is not improper English grammar, CI.

Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo.

That's not a sentence. DUH!

It shorely is, CI.

Not from any English lesson I was taught in.

The English lessons you would have been taught were pretty much a joke, CI. Those "lessons" were the ones that filled the Peeves threads, which are now, mercifully dead, with "lesson" after "lesson".

But not grasping the meaning can happen to anybody and sometimes, what is seemingly ungrammatical, when given the proper context, bursts into grammaticality.

I find "study well and make progress every day" to be the best you've proposed so far.

I'd suggest "diligently" in place of "well."

Study diligently and progress every day.

"Up" is not offensive unless it is paired with "yours." ("Up yours" which means "up your ass.")

Only one 'l' in 'diligence'.