What size wire needed for 150 amp service ?

Not nearly enough information. What's the distance.

From the NEC Code Book: Table 310.15 (B) (6)

150 Amps #1 AWG THWN or XHHW Copper or #2/0 Aluminum

In the most basic of ways Don is correct. Thing is, this was the only answer he could give considering the lack of details provided.

I will add, a 150A service is a useless size these days. There is almost no difference in price between it and a 200A. In most any case it is not at all worth installing a 150A service.