This paper gives us a demonstration of twin primes conjecture using approximation of function Υ that we introduce in section 6. Sections 1 − 5 give us introduction to terminology and a clarification on Υ terms. In particular section 5 is really important because of its Lemma. Section 7 reassume foregoing explanations and it give us two theorems and one corollary; the theorem 7.2 give us exact approximation of twin primes counting function.