Negative urinary protein corresponds to 24-hour urine protein quantification for urine protein less than 150mg/d. Common methods of urine protein testing include 24-hour urine protein excretion rate and random urine albumin/creatinine ratio. 1. 24-hour urine protein excretion rate: less than 150mg/d is negative for urine protein; more than 150mg/d can be diagnosed as proteinuria, i.e., positive for urine protein; more than 3.5g/d is diagnosed as massive proteinuria. 2. Random urine albumin/creatinine ratio: normal should be less than 30mg/g; 30~300mg/g diagnosis of micro-proteinuria; greater than 300mg/g, diagnosis of massive proteinuria. Urine protein characterization and quantification is an important examination of urinalysis, which can be used to reflect renal function and diagnose renal disease, abnormalities, need to consult a doctor in time.