The epilimnelic. total phosphorous coni-entralions ([TP]) over the past 400 years were reconslrut'led for Lake Taibai, baaed on the high resol u I ion a 1 fossil diatom aIdy from one sediment core in that lake an eslab-lislied regional diatom-TP transfer funclion. The resulln indiraled dial, during 1630 AD and 1800-1924 AD, [TP] was low within 50-68 (μg/L; 1630-J 800 AD,[TP] were much higher and changed (iratnnlicalK. wliirli was williin 50 -160 μg/L; 1800-1924 AD,[TP] showed low values with litlle changes (remained alxxil 50 jxg/ L); 1924-1953 AI), [TP] kept tow values, showing slight increase (50-63 μg/ L); From 1950s [TP] began to increase and after 1970 [ TP] exceeded 120 μg/L. Match Analog Technique was used to estimate the validily of I he refonslrnt'tion results and il showed that about eighly percent samples provided reasonable values. The changes lialigns of the rei-onstrutted [TP] revealed that Iwo eutrophicalion stages had occurred and the causes wm、preliminarily discussed. Finally 50 μg/L was propounded to be llie naluralness value for TP index in Lake Taibai, whit'li could be used as the restoration target.