Through instantaneous sample method,we observed 4 Gorilla(Gorilla gorilla) individuals in Shanghai Zoo from September to December 2009 to determine appropriate sampling interval to separate two consecutive observation.The focus animals were active during 10: 00-11: 00 and 14: 00-15: 00,and significant difference in active frequency between individuals was detected.The appropriate sample interval is 3-13 min.Data accuracy would be reduced and data independence would be increase when increase sampling interval.The appropriate sample interval supposed by this study is 2－8 min.Here，a compromised sample interval of 3－8 min is considered.