Objective: To establish a method for determining content of total salvianolic acids in the root of Salvia miltiorrhiza alba(Baihua Danshen)and its extraction. Method: Based on the consistency of the characteristic adsorption bands in the visible absorption spectum between reference substance and sample solution of Baihua Danshen

salvianolic acid B

tanshion sodium and protocatechuic aldehyde were compared using NaNO2-Al(NO3)3 colorimetric method.The best color conditions

which regarded the dosage of color developing agent and placing time in the dark after adding color developing agent as observation factors

were optimized and its methodology was investigated. Result: Salvianolic acid B was selected as the reference substance. The optimized color condition was as follows:precisely add 2.5 mL 1% NaNO2 and place in the dark for 10 min

then accurately add 20%Al (NO3)3 0.25 mL and place in the dark for 10 min

and lastly

precisely add 1 mol·L-1 NaOH 4 mL and place in the dark for 15 min.The linear range was 0.028-0.309 mg(r=0.999 9) and the average recovery was 96.29% and 99.53% for Baihua Danshen and its extraction respectively. The content of total salvianolic acids in five batches of Baihua Danshen was ranged from 5.65% to 6.19% and in the extrations was ranged from 61.03% to 61.96%. Conclusion: The NaNO2-Al(NO3)3 color imetric method for determining content of total salvianolic acids in Baihua Danshen and its extrationis established.