In this study, the effect of ambient temperature on the 45$^{circ}$micro ESR/hr of cattle blood were observed, and a correction chart for correcting observed values at any ambient temperature to standard values at 20$^{circ}C$ was plotted. Besides, the effect of storage temperature of blood on the 45$^{circ}$micro ESR/hr was surveyed. The results were as follows: 1. The values of the 45$^{circ}$micro ESR/hr were increased as the ambient temperature were elevated(P<0.01), and lower the value of PCV, higher the effect of temperature on the 45$^{circ}$micro ESR/hr was observed(P<0.01). 2. Regression of values of 45$^{circ}$micro ESR to ambient temperature in all the group of different level of blood PCV showed linear regression with the highly significant coefficient of correlation. With the results, correction chart was drawn as in Fig. 1. 3. In the purpose to verify the reliability of correction chart, observed values of 45$^{circ}$micro ESR/hr in field(out door) were corrected to values at 20$^{circ}C$ by the correction chart(Fig. 1), comparing with the observed values at 20$^{circ}C$ of standard temperature. No significant differences were found between two groups mentioned above. 4. In the study on the effect of storage temperature of the blood on the 45$^{circ}$micro ESR/hr, group of storage temperature at 5$^{circ}C$ showed statistically no significant differences untill 24 hours in contrast with standard control group.