One of the outlet has no power in my house. I found the neutral wire is also hot like the black wire. There are only two wires, no ground wire involved. The wiring in the house is very new (~ 1 year). What would be the problem?
Any plugged in and turned on device, for example a light bulb, makes a connection between the hot and the neutral. This enables current to flow through the light bulb and power it. If the neutral is disconnected anywhere between the light bulb and the panel, then the neutral from the light to the point of the break in the neutral will become hot (and the device will be unpowered, because no current will be flowing through it). Look for a disconnected neutral.
To test whether you have a broken neutral, turn off everything in the circuit which has the hot neutral. If the neutral is then no longer hot, this confirms that a neutral is disconnected in the circuit.
For the purposes of this test, if you have any lights with 3-way switches in the circuit, you will not know if the light is switched on (and the neutral path broken so the light is not lighting) or if the light is switched off. It might be best to temporarily unscrew any such bulbs. Also, unplug any floor or table lamps because you can't tell it they are switched on or not.
There could be a loose neutral at any connection of the neutrals in wall boxes or at the neutral connection block in the electrical panel. Check the wall receptacle boxes first. Look for evidence of heating of a neutral wire or a loose neutral wire. Are your wires connected to the receptacles by "back stabs" into the receptacles or are they looped around the screws? Do you have copper or aluminum conductors in this circuit?
Because the neutral wire is broken -- but a load is still plugged in downstream, connecting neutral to hot. See the first two illustrations in my answer here, where I describe how it normally works.