Rigging Troubles

Hi All
O.K so i’ve made a character, rigged it, but then when i rotate the bones they come out of mesh. The mesh sort of lags behind abit, if that makes sense. I find it annoying. It only happens on some of my models



probably you have the same vertices assigned to two or more bones?

you also might have the bone envelopes quite large - so they are effecting more than they should