Objective:To investigate the differences of the anorectal motility and perception among functional constipation subtypes. Methods:Functional constipation was categorized according to colon transit time(CTT) and transit index(TI). Four types were divided:normal transit constipation(NTC),slow transit constipation(STC),outlet obstructive constipation(OOC),and mixed type constipation(MC). Anorectal manometry was carried out in all subjects to investigate the anorectal motility and sensory function in patients and the controls. Results:Compared with controls,(1)anal resting pressure in FC patients was significantly higher,while the defecation thresholds and the pressure of urgency were much lower.(2)All subtypes of FC displayed significantly lower anal resting pressure;The defecation thresholds and the pressure of urgency of NTC and OOC were significantly increased ,while STC displayed lower minimum relaxation volume,first sensation,and higher defecation thresholds;No significant difference among four subtypes. Conclusion:(1)Abnormality of anorectal motility and perception is an important pathogenesis of FC;(2)According to the similarity among different groups,there might be some connection in pathomechanism between NTC and OOC;(3)The pathogenesis of STC is complicated. Lots of motility factors should be contributed to its pathogenesis.