The method applied is a direct one tube micromethod that measures rapidly and reliably d-ALA in a urine sample of 100ul. And also shows good linearity between absorbance and added ALA over a wide range of concentration. The test was performed in 79 urine samples, randomly selected in this hospital. 1) The mean value of ALA-U in all the samples is 3.94±2.22(1.72~6.16 ㎎/L.) with variation in according to age group, ie. 4.5±2.8㎎/L. in the group under the age of 10, 4.1±2.2 ㎎/L. in 10~19yrs group and 3.28±1.36㎎/L. in the group of 20~39 years old. 2) The peak frequency of specimen allocated depend on the concentration of ALA-U is in range of 2~2.9 ㎎/L with 32.6%(29 cases). 3) The effect of reaction time(boiling time of reactant) to the recovery rate of ALA added to samples shows at Table 1. ie., the peak recovery rate(98%) found at 15-minutes reaction time. 4) A good linearity (relationship) between the ALA value and its absorbance is noted at Fig. III. ie., Absorbance 0.1 equivalent to 6㎎/L. of ALA concentration(Factor is 60).