A systematic investigation and numerical results of calculation of T2 symmetric deep level wave function induced by short range defect potential in Si are described, based on a recently developement on site defect potential Green's function method. [5,6] Such a complete information of T2 symmetric wave functions in Si is presented for the first time. The occupation probability P1 of the wave function located around four nearest neighbour sites of the defect center has a peak exceeding 50%. This part of wave function could be described by T2 symmetric combination of four hybrid orbital quasi dangling bonds located at four nearest neighbour sites and pointing toward the defect center. The total occupation probability of wave function located on the 0,1,2 shells arround the defect center is about 70%. The rest part of the wave function extends diversely over a wide range of space. The characteristics of the wave function are insensitive to the defect energy over most part of the energy range in the gap. Only when the defect energy level approaches very closely to the band edge of either conduction (Ec) or valence (Ev) band, the aforementioned peak P1 disappears and the wave function extends smoothly all over the space. A T2 symmetric deep level due to ideal vacancy is found at 0.51 eV up to the Ev.