Objective To extract the specific symptoms of TCM syndromes of chronic fatigue （CF）. Methods Epidemiological cluster sampling method was used in this trial. Totally 782 cases of CF patients were selected from universities

secondary schools

primary schools and hospitals of southern Fujian province. The subjects filled in "Scale of Clinical Symptoms of Chronic Fatigue" to record the clinical data of symptoms

tongue

and pulse for the diagnosis of specific TCM symptoms. The random forest （RF） method was adopted to encode the 95 symptoms extracted from the above-mentioned scale to select the main symptoms of common syndromes of CF and to measure the contribution of symptoms to the syndromes. Results Symptom groups of 4 syndromes of CF were achieved. Spleen deficiency syndrome:abdominal distention after eating or in afternoon

loss of appetite

sallow completion

loose stools

and emaciation; Heart deficiency syndrome:palpitation

chest fullness

thready pulse

insomnia or dream-disturbed sleep

and forgetfulness; Liver stagnation syndrome:hot temper or depression

sighing

bitter taste

dry throat

and string-taut pulse; Qi deficiency syndrome:swollen tongue with toothprints

shortness of breath

abrupt breathing

inactive talking

and spontaneous sweating. When the symptoms were inputted to the models

the model prediction accuracy was 96.13%

94.75%

95.89%

and 94.26% respectively. Conclusion The RF method has a good classification function on the syndromes of CF. Spleen deficiency syndrome

heart deficiency syndrome

liver stagnation syndrome

and qi deficiency syndrome are commonly appeared syndromes

each of them is provided with its own specific symptoms.