Background: A Hematuria colorimetric card could unify the description of gross hematuria, but the consistency in assessing hematuria samples of a hematuria colorimetric card for gross hematuria is still inconclusive. The consistency testing and improving of hematuria colorimetric card has potential clinical application value.Methods: According to 6 color scales (0~5), 31 hematuria samples were made. One sample was used to explain the use of hematuria colorimetric cards, and then the evaluator was asked to describe the color. After the remaining 30 samples were arranged in a random number table, 30 evaluators independently completed the hematuria sample assessment under the same conditions. Kendall W coordination coefficient was used to test inter-observer consistency. After 1 hour, 30 hematuria samples were rearranged by random digital table method, 15 of which were randomly selected from 30 evaluators, and 30 samples were evaluated independently under the same conditions. Adopt the method of Kappa to test the consistency of the two evaluation results. Results: In the study, the evaluator lacked unity in describing the same hematuria color, including six groups of descriptive words: gross hematuria, light blood, light red, blood, scarlet, carmine. Inter-observer (inter-group) consistency test, Kendall coordination factor was 0.881(F=766.34), P<0.05), the result indicats higher inter-observer agreement. For intra-observer (intra-group) consistency test, the kappa value of nurses was 0.909~1(P<0.05), the value of doctors was 0.818~0.95(P<0.05), and the value of students was 0.863~0.911(P<0.05), the results showed that intra-observer agreement was also high. Consistency results between grade evaluation results of hematuria samples and standard color numbers: the average consistency of evaluation results of standard color numbers 0~5 was 100%, 100%, 94.2%, 65.2%, 38%, 65.8% respectively. The the 4th color block with low discrimination in the primary hematuria colorimetric card was eliminated, and the 5th color block was reassigned to 4th. Thus the modified hematuria colorimetric card was divided into 5 grades.Conclusions: The improved hematuria colorimetric card has good consistency in hematuria evaluation and is an effective tool for evaluating hematuria grade, which is helpful to unify the evaluation standard of gross hematuria grade.