Objective To investigate the effect of toluene in the quantitative detection of 24 hour(24 h) urine micro protein(MPr) and urine micro albumin(UMA). Methods Eighty-two random urine of the patients with different concentrations were collected.The group without toluene and the other group with toluene were stored at the low, medium and high tempreture for 24 h respectively. Then MPr and UMA were measured in 0 h and 24 h. Paired t-test was used to test whether the difference was statisticallysignificant. Results When stored at the low and medium temperature,the results of immediate detection of MPr and UMA were compared with those of the addition of toluene or without for 24 h. The difference was not statistically significant (P>0.05). However, there was significant difference in MPr and UMA value of urine at high temperature under the same comparison(P<0.05). Stored at the same temperature for 24 hours, the results of MPr and UMA were compared between the adding groups and the non-adding groups. The results showed that there was no significant difference between them. Conclusion The specimens for the quantitative detection of the 24 h MPr and UMA are not need to be added with toluene, and toluene in the urine is not preservatively effective.