“九(jiu)年一(yi)(yi)貫(guan)制”學校(xiao)(xiao)，通常(chang)是指該校(xiao)(xiao)的小(xiao)學和初(chu)中(zhong)(zhong)(zhong)施行一(yi)(yi)體化的教育(yu)，小(xiao)學畢業后可直(zhi)升(sheng)本校(xiao)(xiao)初(chu)中(zhong)(zhong)(zhong)，“小(xiao)升(sheng)初(chu)”原則上不許擇(ze)校(xiao)(xiao)流動(dong)，希望在本校(xiao)(xiao)升(sheng)初(chu)中(zhong)(zhong)(zhong)的學生也不用為上初(chu)中(zhong)(zhong)(zhong)費盡心(xin)思；九(jiu)年一(yi)(yi)貫(guan)制學校(xiao)(xiao)的年級(ji)通常(chang)被(bei)稱為1年級(ji)、2年級(ji)……，至(zhi)9年級(ji)。這樣在學生年齡較小(xiao)，適應能(neng)力較弱的時候(hou)的教育(yu)會有一(yi)(yi)個連貫(guan)性(xing)。

"十(shi)二(er)(er)年(nian)一貫(guan)制學校(xiao)(xiao)"是(shi)指(zhi)集小(xiao)學、初(chu)中(zhong)(zhong)(zhong)和高中(zhong)(zhong)(zhong)為一體(ti)的12年(nian)一貫(guan)制學校(xiao)(xiao)。學校(xiao)(xiao)主要(yao)有三個特點，一是(shi)連貫(guan)性(xing)，學生(sheng)可以從從一年(nian)級(ji)至(zhi)十(shi)二(er)(er)年(nian)級(ji)，相繼完成(cheng)小(xiao)學至(zhi)高中(zhong)(zhong)(zhong)教育，其間(jian)不間(jian)斷、不選拔。二(er)(er)是(shi)就近入(ru)學、取消招生(sheng)考(kao)試。小(xiao)升(sheng)初(chu)直接升(sheng)入(ru)本校(xiao)(xiao)初(chu)中(zhong)(zhong)(zhong)和高中(zhong)(zhong)(zhong)，不必再受小(xiao)升(sheng)初(chu)、中(zhong)(zhong)(zhong)考(kao)折磨之苦。三是(shi)實行統一的學校(xiao)(xiao)行政、教育、教學管(guan)理(li)。

“完全中學”既有初(chu)級中學的學段，又有高級中學學段的學校，是(shi)一種(zhong)學校制度。

初中(zhong)屬(shu)于9年義務教育階段(duan)，而高中(zhong)不(bu)屬(shu)于義務教育，在(zai)學校的(de)設置中(zhong)，已(yi)經(jing)有許多完全中(zhong)學脫鉤為兩所學校。

許(xu)多中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)學(xue)(xue)(xue)同時設立(li)初中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)部及高中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)部，這些(xie)中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)學(xue)(xue)(xue)就是(shi)完全中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)學(xue)(xue)(xue)。不(bu)過(guo)，國家規(gui)定國家級重(zhong)點中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)學(xue)(xue)(xue)和(he)省級重(zhong)點中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)學(xue)(xue)(xue)不(bu)許(xu)開(kai)設初中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，但(dan)是(shi)還(huan)是(shi)有(you)(you)一(yi)(yi)些(xie)學(xue)(xue)(xue)校(xiao)違規(gui)操作。有(you)(you)一(yi)(yi)些(xie)重(zhong)點中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)學(xue)(xue)(xue)通(tong)過(guo)開(kai)辦(ban)分(fen)校(xiao)等形式開(kai)設初中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)，規(gui)避這一(yi)(yi)規(gui)定。由于歷史(shi)的(de)原(yuan)因，一(yi)(yi)些(xie)曾(ceng)經開(kai)設初中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)但(dan)后來取(qu)消了(le)初中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)部或(huo)者不(bu)直接(jie)開(kai)設的(de)，仍然被(bei)稱為完全中(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)(zhong)學(xue)(xue)(xue)。