In this paper, we deal with the problem of uniqueness of rr~rorrorphic functions. It is shown that there exist two finite sets Sj (j= 1, 2) such that any two nonconstant merorrorphic functions f and g satisfying Ef(Sj)=Eg(Sj) for j=l, 2 must be identical, which answers a question posed by Gross.

This paper studies the problem of uniqueness of entire functions that share real zeros and real ones. An example is provided to show that a result of Czubiak and Gundersen is not completely correct. Results in this paper correct the result of Czubiak and Gundersen, and also correct a result of Osgood and Yang.

This paper studies the problem of uniqueness of meromorphic functions and shows that there exist two finite setsSj (j=1, 2) such that any two nonconstant meromorphic functions f and g satisfying Ef (Sj)=Eg (Sj) for j=1, 2 must be identical. The results in this paper improve some theorems given by Nevanlinna7, Brosch8, Yi6 and other authors. As a special case, these results answer an open question posed by Gross5.

In this paper, we show that if two non-constant meromorphic functions f and g satisfy E(aj; k; f)=E(aj; k;g) for j = 1; 2;:::; 5, where aj are live distinct small functions with respect to f and g, and k is a positive integer or 1 with k 14, then f g. As a special case this also answers the longstanding problem on uniqueness of meromorphic functions concerning small functions.

In this paper, we deal with the problem of uniqueness of meromorphic functions sharing three values, and prove some results which are improvements and extensions of many known theorems. Examples are provided to show that the results in this paper are sharp.

In this paper, we deal with the relation between the characteristic functions of meromorphic functions that share three values CM. As applications of our main results, we shall a rmatively settle two conjectures proposed by Mues and Osgood-Yang.

Using the idea of weighted sharing of values, we study the problem of uniqueness of meromorphic functions that share three values. The results in this paper improve all theorems given by Lahiri in Nagoya Math. J. 161 (2001) 193-206. Examples are provided to show that some results in this paper are sharp.

In this paper, we prove a result on uniqueness of meromorphic functions sharing three values counting multiplicity. As applications of this, many known results can be improved. Examples are provided to show that the results in this paper are best possible

In this paper, we deal with the problem of uniqueness of meromorphic functions concerning one question of Gross, and obtain some results that are improvements of that of former authors. Moreover, the example shows that the result is sharp.