How generally we put the Labor coast over the Material ?(In terms of work hour or by percentage)

in term of work Hour because it will be accurate as compare to percentage

We should calculate the numbers of hours the job should take,How much your staff person.

We calculate in terms of percentage

Your are asking about labor cost over material cost

Its answer is only with respective percentage of the item ....

But in terms of accuracy work hours in better than percentage ....

Assuming I understand the question correctly, it would be more accurate to do using hourly rate, or day rates.  As calculating as a percentage of material is not going to be consistent, due to material costs changing as market conditions fluctuate.  Depending on the industry, and country, there should be a set of 'norms' available for the number of hours required to carry out a certain scope of work. Taking this over the cost of the material for the job will give you the percentage if you wish to proceed in this way.

i answer by example : for 1m3 of concrete for piles or foundation, i know based on my experience, that the reatio is 2hours/m3, for steel reinforcment is different it is by excperience 0.067$/kg  for example