Study on the changes of soil enzyme activity and microbial biomass after paddy field was abandoned in wetland system can provide reference for protecting wetland. Top soils were collected from wetland with Phragmites communis (PW), wetland with Cyperus rotundus (CW), abandoned rice field (with dominant vegetation of Paspalum distichum and Alternanthera sessilis) (AF), and rice paddy field (with Oryza sativa) (RF) in Huixian karst wetland, Guilin, China. The soil enzyme activities and micro-biomass were detected using colorimetry and chloroform fumigation-extraction, respectively. The results showed that the micro-biomass carbon (MBC) in the RF was (345.20±30.06) mg/kg, which was significantly lower than that in PF and not significantly difference with that in PW and CW. The micro-biomass nitrogen (MBN), microbial DNA, invertase activity and alkaline phosphatase activity in RF were (48.03±18.48) mg/kg, (5.65±1.48) μg/kg, (19.16±1.43) mg g^-1 (24h)^-1, (2.20±0.94) mg g^-1 (2h)^-1, respectively, which were significantly lower than those in PF and no significant difference with those in PW and CW. Principal component analysis showed that the points of AF could be well separated from those of PF, but not separated from those of PW and CW. The statistical analysis showed that MBC and alkaline phosphatase activity were positively correlated with pH (P<0.05); MBN, invertase activity and alkaline phosphatase activity were all positively correlated with SOC (P<0.05); soil microbial DNA was positively correlated with SOC (P<0.01), TN (P<0.01), AN (P<0.01) and Mg²⁺ (P<0.05). The above results indicated that pH, SOC, TN, AN and Mg²⁺ decreased, resulting in significant decreases of soil microbial biomass and two enzyme activities after a paddy field was abandoned. Therefore, we suggest that Oryza sativa could be replanted in AF to accelerate the recovery process of Huixian karst wetland.