Justinian code has unquestionably formed the basis for many codes of law in countries around the world today. do you think the laws of today in the united states are stricter than those laws of roman time? provide examples to support your opinion

This is definitely a “History” or “Politics & Government”” question, not “Travel” and I agree with Sue, you’re avoiding doing your own homework. I’m not going to do it for you, but I’ll try and put you on the right track.
The “Roman” institutions (caro amico napoletano, il ragazzo sta parlando della Roma antica, anzi di Bisanzio, che aveva un principio legislatvo ben diverso dal nostro, uno che “funzionava” per essere chiari) definitely influenced the Founding fathers. Some aspects are obvious (The Senate, Governors of Roman Provinces/US States, Ethics) others are less obvious (Representation, civil Rights of citizens, Fiscal system).
The basic differences are of “anglo saxon” inspiration (Pursuit of happiness, Common law, Inviolability of office).
The end result is a very interesting combination of both, which should make US citizens proud of their constitution and system of Government.
Compare Obama’s political platform with the Gracchi brothers, and both Bushes with the Dictator Sulla. You should get quite an interesting result.
The Justinian Code came very late in Roman History, when “Rome” had ceased to exist, and it’s spirit continued to live in Byzantium, in a very watered “Greek” community. In terms of law making, it is certainly interesting, because it is an attempt to sum up all that was positive in the “inherited system”, but it should not be taken out of it’s Historical context, unless you believe the US has reached the same stage of “decline”, which I don’t.
Stricter laws in Roman times? I would say more Draconian, according to the times.
Look up a description of Gibbons’ “Decline and Fall of the Roman Empire” and you should have enough background data to write your paper.