The BQV and PQV methods were used to analyze the pattern of spatial distribution of Scotch pine in the sandy area in Northeast China.

Using the data of soil factor,total vegetation coverage and the number of species on each sampling quadrate in a 100-metre-long continuous sample belt,depending on the sample analysis of variance methods(BQV,TTLQV,PQV),calculate every variance in different areas,to find the existence of around 6-7m radius of gathered scale distribution pattern for the vegetation in the investigation sample belt.

in this paper we give sufficient and necessary conditions that sample avarages and sample variances .

By the derivations and comparisons of Sampling Variance formulas under the different Sampling Methods,it is proposed that Sampling Method depend upon two parameters:heteroskedasticity r and intercept α.

Acquired conclusion was that the sample mean value submitted to normal distribution, and the sample variance was composed of a number of linear sum of random variable submitted to Chi-Squared distr.

The estimators of functions G(t) and F(t) are extended to function J(t) and the comparative study is made,including the comparison of biases,sample variances and maximal bias.

In view of this situation, taking the samples from the entrance exam papers of art for higher education in He′nan Province in 2000 and the sample variance method and relative frequency method were used to evaluate the accuracy and stability of grading, moreover, the curve line of errors has been formed.