please tell me duartion of bachelor degree in england .specially in science.& engg.

Most bachelor degrees in the uk are 3 years long

Just to clarify though, that this is a forum for postgraduate studies (Masters, PhD etc), so whilst we'd be happy to answer undergraduate questions (we've all been through it!) there might be an undergradaute forum elsewhere on the internet too.

You could have easily googled this.

There are also BSc degrees with a year in industry, so that makes them 4 years.

I think there might be fast-track two year degrees as well.