I got call from a CEO of publishing Co. How much is my Non-fiction book worth. None on market of its kind.?

if the CEO called you personally than it is probably worth a lot. also, once you figure out how much it is worth, tell them a price a good amount over that because that way you have room to negotiate. you need to fight for as much as can get because they will try to convince you that it is less. if there is nothing else on the market then you have an even greater advantage because it is very unique. it can also help if you get a competitive offer from another publishing company because you can play them off each other to get the most money. remember you spent a lot of time on the book and you deserve your fair share of the profits. you could also probably try to get paid a percentage of every book sold. depending on how long you spent on the book and how serious about it, it could be a good idea to get a lawyer/agent to work it out for you because they will know how to negotiate with publishing companies.