I did encode an anime Movie with Subtitles.The Movie had a length of about 124Minutes.I used the KVCD Plus Templates(120Min/80Min CD-R).After the encoding process was finished i saw that the output Mpeg file had size of about 880-890MB.

Is that normal???

Of course I know that the input Film had length of 124Min but i don`t think that 4 Minutes of Extra Time will put out 90 Megabytes of Extra Size.

Does the Fact that the input Movie contains Subtitles and that it is an anime cause the relativly big file size???

As Kwag might say:

You should also try a GOP matrix of 1-15-3-1-15 (as posted somewhere else in this forum) or 1-12-2-1-24 (check whether of the two gives you better compression, or higher quality for a given filesize, which is the same).
And last but not least, I shall mention that the use of some SansGrip filters gave me very good results for anime. To use them include the following in your avisynth script:

• FluxSmooth()
  Blockbuster( method="noise", detail_min=1, detail_max=10, variance=1, seed=1 )