Thermohaline staircases are a strikingly organized structure in the ocean which is characterized by a series of vertically well mixed layers of both heat and salt separated by sharp interfaces. Half a century after its first discovery, we are only half-way towards a completely understanding of its formation mechanism. In mid/low latitude region where the salty and warm water lies above the relatively colder and fresher water, the formation of the staircase structure has been believed to be well explained using the gamma instability theory proposed by Radko (2003). However, in the polar region where staircases are observed to exist in a way that the cold fresh water lies above the relatively saltier and warmer water, the equally promising explanation does not yet exist. Here we will discuss our new theory that explains the formation of staircases in polar ocean which is built up based on the instability of the stratified turbulence flux laws. We believe this new theory will lead to a final explanation for the polar ocean staircases.