I have no doubt both will work well for your application.. but Focusrite has been making interfaces for a longer time and their driver system is well proven..
I'd go with the 2i2.. you can also check Presonus who give great value for the money.

loturow, post: 461248, member: 51613 wrote: Which is better as sound card feature ? for electronic piano recording and vocal and guitar recording i buying for home studio please help.

As pc said, the Focusrite is likely to be a better unit for your acoustic recording. Here in the UK, Focusrite products tend to be relatively cheaper than the imported Presonus equivalent boxes. In the US (and probably Canada), it could be that the reverse is true.

Both of the audio interfaces (not sound cards, which sit inside a computer chassis) that you linked to are 2-channel recording devices. I'm assuming you would be recording the piano at a different time from the vocal and guitar, but by going for a 2-channel interface, you would have to keep plugging and unplugging between the piano pair of inputs and the microphone/guitar. It's worth considering this aspect before plumping for a 2-channel unit, since 4-channel interfaces are not that much higher cost, and can save frustration, errors and connector wear.

+1 on focusrite.

I use a Focusrite for my homestudio, a Saffire Pro 40, and am happy with it. Before this one I had a Lexicon FW410 which was much duller and lacked a lot of things. The only good thing was it had a lexiverb in the monitor path and type 4 conversion from DBX - but still my Focusrite sounds more open and crisp. Now I have a Lexicon MPX-1 inserted in the monitor path to provide some reverb and delay in the minitor signal if a singer/musician wants this.