2004年,在世界(jie)杯短池(chi)賽俄羅斯站200米混合泳中,劉子(zi)歌獲(huo)得金(jin)牌(pai)。同年,隨(sui)著(zhu)教練(lian)金(jin)煒轉會到上(shang)(shang)海,成(cheng)為(wei)上(shang)(shang)海寶山體育局寶山游(you)泳學(xue)校的一名(ming)學(xue)生。?
2005年(nian),劉子(zi)歌進入上海游泳隊。?
2007年,進入中國(guo)國(guo)家隊。
2008年4月(yue),在全國(guo)游泳(yong)冠軍賽暨(ji)奧運(yun)會(hui)選(xuan)拔賽中獲得(de)女子200米蝶泳(yong)冠軍,并(bing)取得(de)北京奧運(yun)會(hui)參(can)賽資格;8月(yue)14日,劉子歌在北京奧運(yun)會(hui)女子200蝶泳(yong)比賽中,以(yi)2分04秒18獲得(de)金牌,并(bing)打破了世界紀錄(lu)。
2009年4月(yue)(yue),在(zai)全國游(you)(you)泳(yong)(yong)(yong)冠(guan)軍(jun)賽(sai)(sai)200米(mi)(mi)蝶(die)(die)泳(yong)(yong)(yong)獲(huo)(huo)得(de)(de)(de)銀牌,7月(yue)(yue),在(zai)羅馬世錦(jin)賽(sai)(sai)獲(huo)(huo)得(de)(de)(de)200蝶(die)(die)泳(yong)(yong)(yong)亞軍(jun),10月(yue)(yue),在(zai)十(shi)一運會上(shang),以(yi)(yi)56秒(miao)07獲(huo)(huo)得(de)(de)(de)100米(mi)(mi)蝶(die)(die)泳(yong)(yong)(yong)冠(guan)軍(jun),并(bing)打破亞洲紀錄(lu);以(yi)(yi)2分(fen)01秒(miao)81獲(huo)(huo)得(de)(de)(de)200米(mi)(mi)蝶(die)(die)泳(yong)(yong)(yong)冠(guan)軍(jun),超過了澳大(da)利亞選手斯奇普保持(chi)的(de)2分(fen)03秒(miao)41的(de)世界紀錄(lu);還與(yu)隊(dui)友(you)合(he)作(zuo)獲(huo)(huo)得(de)(de)(de)女(nv)(nv)(nv)子(zi)(zi)4×100米(mi)(mi)混合(he)泳(yong)(yong)(yong)金(jin)牌。11月(yue)(yue),在(zai)世界杯短(duan)池(chi)游(you)(you)泳(yong)(yong)(yong)系列(lie)賽(sai)(sai)斯德哥(ge)爾摩站,以(yi)(yi)2分(fen)02秒(miao)50獲(huo)(huo)得(de)(de)(de)金(jin)牌,并(bing)打破了世界紀錄(lu)。在(zai)國際泳(yong)(yong)(yong)聯短(duan)池(chi)游(you)(you)泳(yong)(yong)(yong)世界杯賽(sai)(sai)柏(bo)林站,獲(huo)(huo)得(de)(de)(de)女(nv)(nv)(nv)子(zi)(zi)200米(mi)(mi)蝶(die)(die)泳(yong)(yong)(yong)冠(guan)軍(jun),以(yi)(yi)2分(fen)00秒(miao)78打破世界紀錄(lu)。同年12月(yue)(yue),獲(huo)(huo)得(de)(de)(de)第五(wu)屆東亞運動會女(nv)(nv)(nv)子(zi)(zi)200米(mi)(mi)蝶(die)(die)泳(yong)(yong)(yong)金(jin)牌、亞洲游(you)(you)泳(yong)(yong)(yong)錦(jin)標賽(sai)(sai)女(nv)(nv)(nv)子(zi)(zi)200米(mi)(mi)蝶(die)(die)泳(yong)(yong)(yong)金(jin)牌。2010年2月(yue)(yue),在(zai)短(duan)池(chi)游(you)(you)泳(yong)(yong)(yong)世錦(jin)賽(sai)(sai)女(nv)(nv)(nv)子(zi)(zi)200米(mi)(mi)蝶(die)(die)泳(yong)(yong)(yong)決(jue)賽(sai)(sai)中,劉子(zi)(zi)歌開始150米(mi)(mi)一路領先,但后勁不足,最終以(yi)(yi)2分(fen)04秒(miao)78僅列(lie)第五(wu)。在(zai)女(nv)(nv)(nv)子(zi)(zi)4×100米(mi)(mi)混合(he)泳(yong)(yong)(yong)接力中,與(yu)隊(dui)友(you)合(he)作(zuo)獲(huo)(huo)得(de)(de)(de)金(jin)牌。
2011年(nian)(nian)4月,在全國游泳(yong)(yong)冠軍(jun)賽,獲(huo)得(de)女(nv)子(zi)(zi)50米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)第(di)五名(ming)(ming)、100米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)冠軍(jun)、200米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)冠軍(jun)。同(tong)(tong)年(nian)(nian)11月,在短(duan)(duan)池(chi)世界(jie)杯北(bei)京(jing)站女(nv)子(zi)(zi)100米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)獲(huo)得(de)第(di)四名(ming)(ming)、女(nv)子(zi)(zi)200米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)第(di)四名(ming)(ming)。同(tong)(tong)年(nian)(nian)8月,在倫敦(dun)奧(ao)運會女(nv)子(zi)(zi)200米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)僅獲(huo)得(de)第(di)八(ba)名(ming)(ming)。同(tong)(tong)年(nian)(nian)11月,短(duan)(duan)池(chi)游泳(yong)(yong)世界(jie)杯系列賽北(bei)京(jing)站獲(huo)得(de)女(nv)子(zi)(zi)100米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)第(di)五名(ming)(ming)、女(nv)子(zi)(zi)200米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)第(di)三名(ming)(ming);同(tong)(tong)年(nian)(nian)12月,世界(jie)短(duan)(duan)池(chi)游泳(yong)(yong)錦(jin)標賽獲(huo)得(de)女(nv)子(zi)(zi)100米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)獲(huo)得(de)第(di)二名(ming)(ming)、女(nv)子(zi)(zi)200米(mi)(mi)(mi)(mi)(mi)蝶(die)泳(yong)(yong)第(di)四名(ming)(ming)。
2013年,全(quan)國游泳(yong)(yong)冠軍賽女子200米(mi)蝶泳(yong)(yong)獲(huo)得第二名;同年8月,世界游泳(yong)(yong)錦標賽女子200米(mi)蝶泳(yong)(yong)獲(huo)得冠軍。