Abstract: The hair samples of 36 smokers and 10 passive smokers were extracted with 5% sodium hydroxide water solution under ultrasonic and the contents of nicotine and cotinine were determined by ultra performance liquid chromatography(UPLC).The results indicated that:1) the recoveries of nicotine and cotinine were from 98.5% to 101.6% with RSDs of 3.52% and 2.99%,respectively;2) nicotine was detected in all samples,while cotinine was detectable only in samples of smokers;3) the nicotine content in hair mainly affected by smokers' smoking age and average number of cigarettes smoked daily rather than their physiological ages;4) the content of cotinine in hair mainly depended on smoker's smoking age,while slightly correlated with average number of cigarettes smoked daily or smoker's physiological age.This method is simple,accurate,repeatable and can be used for rapid analysis of nicotine and cotinine in batches of hair samples.