how to detect that the site is scam site

Ok, if you really want to know whether the site is a scam, do logical things. CAll up the company, look into the creditials it has, where is it set-up. Call with the relevant authorities it seems to be based on, look under business/company files associated with the website. Seek for opinion "like us". See whether the whole thing is supported with real construction/projects/investment/anything. If youare able to check out them and confirm they are real, then good luck you have done it.

look the whois name in site,who is the owners,where that site buy,

You can check with the Better Business Bureau(BBB).I haven't done so personally myself but many people have said that it is a site which gives info on the genuine and scam sites.

You can check with the Better Business Bureau(BBB).I haven't done so personally myself but many people have said that it is a site which gives info on the genuine and scam sites.

look the whois name in site,who is the owners,where that site buy,